True or False: In sympathetic nervous system, the pre-ganglionic neurons are short, while the post-ganglionic neurons are long.
True
The opposite is true for the parasympathetic division, where the pre-ganglionic neurons are long and the post-ganglionic neurons are short.
True or False: In sympathetic nervous system, one pre-ganglionic neuron can synapse to about 15-20 post-ganglionic neurons.
True
Consequently, activation of the sympathetic nervous system tends to result in a more massive and diffuse reaction than does parasympathetic division.
Cranial nerve which is responsible for 75% of the efferent component of the entire parasympathetic division
A) Vagus (X)
Neurons composing the preganglionic fibers of the sacral portion exit the spinal cord via which nerves?
D) Pelvic splanchnic nerves
True or False: If an organ is innervated by both the sympathetic and parasympathetic divisions, a physiologic antagonism typically exists between these divisions.
True
True or False: Peripheral arterioles have parasympathetic innervation.
False
Peripheral arterioles only have sympathetic innervation. Alpha-1 and -2 receptors mediate vasoconstriction of skin and viscera, while beta-2 receptors mediate vasodilation of skeletal muscles and liver.
True or False: In a sympathetic response, radial muscles of the eyes relax and the ciliary muscles contract.
False
During a sympathetic response, radial muscles of the eye contract via alpha-1 receptors and ciliary muscles relax via beta-2 receptors. The opposite occurs in s parasympathetic response.
The following organs have no parasympathetic innervation, except:
D) Urinary bladder
Kidneys, liver, fat cells, arterioles, and sweat glands do not have parasympathetic innervation.
True or False: In a parasympathetic response, the detrusor muscle of the urinary bladder contracts, while the trigone and sphincter relax.
True
The opposite occurs in a sympathetic response.
Structure which synthesizes and secretes epinephrine and norepinephrine directly into the bloodstream
A) Adrenal medulla
True or False: The secretion from the adrenal medulla contains about 80% norepinephrine and 20% epinephrine.
False
The secretion from the adrenal medulla contains about 80% epinephrine and 20% norepinephrine. These two hormones are fairly similar in action, except that epinephrine increases cardiac function and cellular metabolism to a greater extent because it has higher affinity for beta receptors.
True or False: Aside from adrenal medulla, sympathetic post-ganglionic nerve terminals also synthesize and secrete epinephrine and norepinephrine.
False
Post-ganglionic nerve terminals only synthesize and secrete norepinephrine.
Acetylcholine is the transmitter at the pre-ganglionic to post-ganglionic synapse in both sympathetic and parasympathetic divisions. It is also the transmitter at the parasympathetic post-ganglionic to effector cell synapse.
C) Both statements are true.
True or False: All sympathetic post-ganglionic neurons use norepinephrine and are referred to as adrenergic.
False
Most, not all, sympathetic post-ganglionic neurons use norepinephrine and are referred to as adrenergic. Few sympathetic post-ganglionic neurons are cholinergic in nature and they innervate sweat glands and blood vessels.
Cholinergic receptors are subdivided into two categories: nicotinic and muscarinic. Muscarinic receptors are located between pre-ganglionic and post-ganglionic neurons in both sympathetic and parasympathetic pathways, whereas nicotinic receptors are located between post-ganglionic neurons and terminal effector cell.
A) Only the first statement is true.
Nicotinic receptors are located between the pre-ganglionic and post-ganglionic neurons in both sympathetic and parasympathetic pathways, whereas muscarinic receptors are located between post-ganglionic neurons and terminal effector cell.
True or False: Alpha-1 receptors modulate the release of neurotransmitters from the pre-synaptic terminal, serving as a form of negative feedback.
False
Alpha-2 receptors modulate the release of neurotransmitters from the pre-synaptic terminal, serving as a form of negative feedback.
Alpha-2 receptors are also found on spinal interneurons, and stimulation of these receptors may decrease the neurotransmitter release and diminished stimulation of interneurons that influence the alpha motor neuron. Thus, alpha-2 agonists can be used to manage spasticity.
C) Both statements are true.
Tizanidine, an alpha-2 agonist, is used as an anti-spasticity agent.
True or False: Alpha-1 receptors are primarily located in the smooth muscles of various tissues throughout the body.
True
Beta-1 receptors are primarily found in the following structures, except:
B) Kidneys
Beta-2 receptors are primarily found in certain vasculatures, bronchioles, gallbladder, and uterus. Meanwhile, beta-1 receptors are primarily found in heart and kidneys.
The following results from stimulation of muscarinic receptors, except:
C) Bronchiole smooth muscle dilation
It should be bronchiole smooth muscle contraction.
The following results from stimulation of alpha-1 receptors, except:
B) intestinal smooth muscle contraction
It should be intestinal smooth muscle relaxation. Other responses are urinary sphincter contraction and spleen capsule contraction.
The following results from stimulation of alpha-2 receptors, except:
A) Increased norepinephrine release from presynaptic terminals of peripheral adrenergic synapses
It should be decreased norepinephrine release from presynaptic terminals of peripheral adrenergic synapses.
The following results from stimulation of beta-1 receptors, except:
D) None of these
The following results from stimulation of beta-2 receptors, except:
D) None of these
Other responses are decrease motility of gastrointestinal tract, increased cellular metabolism of skeletal muscle and liver cells, and gallbladder relaxation.
Which of the following is not true about the cerebrum?
A) Its lobes are named from bones of the cranium over which they lie.
Its lobes are named from the bone of the cranium under which they lie.
The cavity present within each cerebral hemisphere is called
D) Lateral ventricle
The lateral ventricles communicate with the third ventricle through the
B) Interventricular foramina
True or False: Unlike the spinal cord, the brain is composed of inner core of gray matter, which is surrounded by an outer covering of white matter.
False
Unlike the spinal cord, the brain is composed of inner core of white matter, which is surrounded by an outer covering of gray matter.
There are 12 pairs of cranial nerves, which leave the brain and pass through foramina in the skull. There are 32 pairs of spinal nerves, which leave the spinal cord and pass through intervertebral foramina in the vertebral column.
B) Only the first statement is true.
There are only 31 pairs of spinal nerves, not 32.
The spinal nerves are named according to the regions of the vertebral column with which they are associated. Which of the following is an incorrect match?
B) 4 coccygeal
There is only 1 coccygeal nerve, but there are 4 coccygeal vertebra.
The anterior root of the spinal nerve consists of bundles of nerve fibers carrying impulses towards the central nervous system. Such nerve fibers are called efferent fibers.
D) Only the second statement is true.
The anterior root of the spinal nerve consists of bundles of nerve fibers carrying impulses away from the central nervous system.
True or False: Because of the disproportionate growth in length of the vertebral column during development, compared with that of the spinal cord. the length of the roots progressively increases from above downward.
True
In the upper cervical region, the spinal nerve roots are short and run almost horizontal. Meanwhile, the roots of the lumbar and sacral nerves below the level of termination of the cord form a vertical leash of nerves around the filum terminale.
Sensory ganglia are fusiform swellings situated on the posterior root of each spinal nerve just proximal to the root's junction with a corresponding anterior root. Similar ganglia are also found along the course of the following cranial nerves, except:
C) CN II
Sensory ganglia are also found along the course of cranial nerves V, VII, VIII, IX, and X.
Which of the following is not true about the early development of nervous system?
B) The neural plate, which is pear shaped and wider caudally, develops a longitudinal neural groove.
The neural plate, which is pear shaped and widercranially, develops a longitudinal neural groove.
Fusion of the neural folds starts about midpoint along the groove and extends cranially and caudally so that in the earliest stage, the cavity of the tube remains in communication with the amniotic cavity through the anterior and posterior neuropores.
The posterior neuropore closes first, and 2 days later, the anterior neuropore closes. Normally, the neural tube closure is complete within 30 days.
D) Both statements are false.
The anterior neuropore closes first, and 2 days later, the posterior neuropore closes. Normally, the neural tube closure is complete within 28 days.
The following adult structures are part of the forebrain, except:
B) Cerebellar hemisphere
Because the spinal cord is shorter than the vertebral column, the spinal cord segments do not correspond numerically with the vertebrae that lie at the same level. Which of the following statements is true about the vertebral levels and their corresponding spinal cord segments?
D) The third cervical vertebra lies opposite the fourth cervical spinal cord segment.
Which of the following is not true about cervical disc herniations?
B) Lateral protrusion of the disc between the fifth and sixth cervical vertebrae may compress the C5 spinal nerve or its roots.
Each spinal nerve emerges above the corresponding vertebra; thus, the lateral protrusion of the disc between the fifth and sixth cervical vertebrae may compress the C6 spinal nerve or its roots.
Which of the following is true about lumbar disc herniations?
A) Pressure on anterior roots causes muscle weakness of ankle dorsiflexors and plantarflexors if the fifth lumbar and the first sacral motor roots are involved respectively.
The discs usually affected are those between the fourth and fifth lumbar vertebra and between the fifth lumbar vertebra and the sacrum.
A lateral herniation may press on one or two roots and often involves the nerve root going to the intervertebral foramen just below.
The nucleus pulposus occasionally herniates directly posteriorly, and if it is a large herniation, the whole cauda equina may be compressed, producing paraplegia.
If this segment of the vertebral column becomes fractured and dislocated, it will result to a severe spinal cord injury
D) Thoracic
Because of the small size of the vertebral canal in the thoracic vertebra, severe injury to this region of the spinal cord results following fracture dislocation.
The spinal cord has
A) Anterior and posterior roots of a single spinal nerve attached to a single segment
an outer covering of white matter and an inner core of gray matter
a central canal that is situated in the gray commissure
a tapering below that forms the conus medullaris
The medulla oblongata has
C) the spinal cord directly continuous with its lower end in the foramen magnum.
a conicalshape
the fourth ventricle lying posterior to its upperpart
the pons directly continuous with its upper border
The midbrain has
A) a cavity called cerebral aqueduct
a cavity that opens above into the third ventricle
a location in the posterior cranial fossa of the skull
a small size
Which of the following is correct about cerebellum?
C) The vermis is the part joining the cerebellar hemispheres together
The cerebellar cortex is composed of gray matter.
The cerebellum lies posterior to the fourth ventricle.
The dentate nucleus is a mass of gray matter found in each cerebellar hemisphere.
Which of the following is true about the cerebrum?
A) The internal capsule is an important collection of nerve fibers, which has the caudate nucleus and the thalamus on its medial side and the lentiform nucleus on its lateral side.
The lobes of the cerebral hemisphere are named for the skull bonesunder which they lie.
The cerebral hemispheres are separated by a fibrous septum called the falx cerebri.
The cavity present within each cerebral hemisphere is called lateral ventricle.
Which of the following is not true about the peripheral nervous system?
A) A spinal nerve is formed by the union of an anterior and a posterior ramus in an intervertebral foramen.
A spinal nerve is formed by the union of an anterior and a posterior roots, not ramus in an intervertebral foramen.
The following statements concern the central nervous system, except:
A) The lateral ventricles are in direct communication with the fourth ventricle.
The lateral ventricles are in indirect communication with the fourth ventricle.
The following statements are true about the cerebrospinal fluid, except:
B) Compression of the internal jugular veins in the neck lowers the cerebrospinal fluid pressure.
Compression of the internal jugular veins in the neck should raise the cerebrospinal fluid (CSF) pressure as it inhibits the absorption of CSF in the arachnoid granulations. In Queckenstedt sign, there is failure of CSF pressure to rise due to blockage in the subarachnoid space.
Obstetricians use caudal anesthesia to relieve pains during the first and second stages of labor. The advantage is that when anesthetic is administered by this method, the infant is not affected.
D) Both statements are true.
True or False: Fractures of the skull are common in children, but are less common in adults.
False
Fractures of the skull are common in adults, but are less common in children. In infants, the skull bones are more resilient and are separated by fibrous sutural ligaments. In adults, the inner table of the skull if brittle and the sutural ligaments begin to ossify during middle age.
Blows to the vault of the skull often result in a series of linear fractures which radiate out through the thick areas of the bone. The petrous parts of the temporal bones and frontal crests strongly reinforce the base of the skull and tend to deflect linear fractures.
D) Both statements are false.
Blows to the vault of the skull often result in a series of linear fractures which radiate out through the thin areas of the bone. The petrous parts of the temporal bones and occipital crests strongly reinforce the base of the skull and tend to deflect linear fractures.
The anteroposterior movement of the brain is limited by the attachment of the superior cerebral veins to the superior sagittal sinus. Meanwhile, the lateral displacement of the brain is limited by the tentorium cerebelli.
A) Only the first statement is true.
The lateral displacement of the brain is limited by the falx cerebri.
Blows on the front or back of the head lead to displacement of the brain, which may produce severe cerebral damage. Blows to the side of the head produce less cerebral displacement, and the injuries to the brain consequently tend to be less severe.
True or False: The posterior division of the middle meningeal artery is the most commonly damaged artery in epidural hemorrhage.
False
The anterior division of the middle meningeal artery is the most commonly damaged artery in epidural hemorrhage. A minor blow to the side of the head, resulting in fracture of the skull in the region of the anterior inferior portion of the parietal bone may sever this artery.
Subdural hemorrhage results from tearing of the inferior cerebral veins where they enter the superior sagittal sinus. The cause is usually a blow to the front or back of the head, resulting in excessive anteroposterior displacement of the brain within the skull.
C) Only the second statement is true.
Subdural hemorrhage results from tearing of the superior cerebral veins where they enter the superior sagittal sinus.
Subarachnoid hemorrhage results from nontraumatic leakage or rupture of a congenital aneurysm on the cerebral arterial circle, or less commonly from an arteriovenous malformation. The symptoms are insidious in onset, and will include severe headache, stiffness of the neck, and loss of consciousness.
C) Only the first statement is true.
The symptoms are sudden in onset, and will include severe headache, stiffness of the neck, and loss of consciousness.
Which of the following is not true about cerebral hemorrhage?
B) Cerebral hemorrhage is generally due to rupture of the thin-walled recurrent artery of Heubner.
Cerebral hemorrhage is generally due to rupture of the thin-walled lenticulostriate artery, a branch of the middle cerebral artery.
All of the following are true about the shaken-baby syndrome, except:
B) Epidural and subarachnoid hemorrhages can be readily detected on CT or MRI scans.
Subdural and subarachnoid hemorrhages can be readily detected on CT or MRI scans.
A 23-year old woman was unconscious when admitted to the emergency department. While crossing the road, she head been hit on the side of the head by a bus. Within an hour, she was found to have a large dough-like swelling over the right temporal region. Select the most likely cause of the swelling.
D) Rupture of the right middle meningeal vessels
A 23-year old woman was unconscious when admitted to the emergency department. While crossing the road, she head been hit on the side of the head by a bus. Within an hour, she was found to have a large dough-like swelling over the right temporal region. She also had signs of muscular paralysis on the left side of the body. Select the most likely cause of muscular paralysis.
A) Rght-sided epidural hemorrhage
A 69-year old man was admitted to the neurology unit complaining of severe discomfort of the lower back. Radiologic examination of the lumbar region of the vertebral column revealed significant narrowing of the spinal canal caused by advanced osteoarthritis. What is the likely cause of discomfort in his lower back?
A) Compression of the cauda equina
True or False: Normal neurons in the mature individual do not undergo division and replication.
True
Type of neuron in which the cell body has a single neurite that divides a short distance from the cell body into two branches, one proceeding to some peripheral structure and the other entering the central nervous system
B) Unipolar
Examples of this form of neuron are found in the posterior root ganglion.
Bipolar neurons possess an elongated cell body, from each end of which a single neurite emerges. Examples of this type of neuron are found in the retinal bipolar cells and cells of the sensory cochlear and vestibular ganglia.
C) Both statements are true.
A Golgi type I neuron has a short axon and short dendrites, giving it a star-shaped appearance. Meanwhile, a Golgi type II neuron has a long axon.
C) Both statements are false.
A Golgi type Ineuron has a long axon. Meanwhile, a Golgi type II neuron has a short axon and short dendrites, giving it a star-shaped appearance.
Golgi type I neurons are found in the following structures, except:
B) Granule cells of cerebellar cortex
Golgi type II neurons are found in the granule and stellate cells of the cerebellar cortex. They greatly outnumber Golgi type I neurons and are often inhibitory in function.
Which of the following is not a characteristic of the nucleus of the nerve cell body?
D) The nucleus is dark, and the fine chromatin granules are widely dispersed.
The chromosomes are not arranged as compact structures but exist in an uncoiled state. Thus, the nucleus is pale, and the fine chromatin granules are widely dispersed.
Which of the following is not true about the nuclear envelope?
B) It is not continuous with the endoplasmic reticulum of the cytoplasm.
It is continuous with the endoplasmic reticulum of the cytoplasm. Therefore, the nucleoplasm and the cytoplasm can be considered functionally continuous. Newly formed ribosomal subunits can be passed into the cytoplasm through the nuclear pores.
All of the following are true about the Nissl substance, except:
A) It is composed of smooth-surfaced endoplasmic reticulum arranged in the form of broad cisternae stacked one on top of the other.
It is composed of rough-surfaced endoplasmic reticulum arranged in the form of broad cisternae stacked one on top of the other.
Which of the following is incorrect about the Golgi complex?
D) It appears as clusters of flattened cisternae and small vesicles made up of rough endoplasmic reticulum.
It appears as clusters of flattened cisternae and small vesicles made up of smooth endoplasmic reticulum.
Mitochondria are scattered throughout the cell body only. These structures possess many enzymes, which are localized chiefly on the outer mitochondrial membrane.
C) Both statements are false.
Mitochondria are scattered throughout the cell body, dendrites, and axons. These structures possess many enzymes, which are localized chiefly on the inner mitochondrial membrane (thrown into folds or cristae that project into the center of the mitochondrion).
All of the following are true about cell transport, except:
D) Rapid cell transport is brought about by three motor proteins associated with ATP-ase sites.
Rapid cell transport is brought about by two motor proteins associated with ATP-ase sites: kinesin for anterograde (away from the cell) movement and dynein for retrograde movement. The direction and speed of the movement of an organelle can be brought about by the activation of one or both motor proteins.
Which of the following is not true about lysosomes?
A) They exist in two forms.
Lysosomes exist in three forms:
(1) primary lysosomes, which have just been formed
(2) secondary lysosomes, which contain partially digested materials (myelin figures)
(3) residual bodies, in which enzymes are inactive and the bodies have evolved from digestible materials such as pigment and lipid
Lipofuscin occurs as yellowish-brown granules within the cytoplasm. It is formed as a result of lysosomal activity, and represents a harmful metabolic by-product.
B) Only the first statement is true.
It is formed as a result of lysosomal activity, and represents a harmless metabolic by-product. It also accumulates with age.
Melanin granules are found in the cytoplasm of cells in the midbrain. Their presence may be related to the cathecholamine-synthesizing ability of these neurons, whose neurotransmitter is dopamine.
B) Both statements are true.
Substantia nigra is found in the midbrain.
True or False: The plasma membrane is composed of an inner and an outer layer of very loosely arranged protein molecules, separated by a middle layer of lipid.
True
The lipid layer of the plasma membrane is made up of two rows of phospholipid molecules arranged so that their hydrophilic ends are in contact with each other and their polar ends are in contact with the protein layers. Certain protein molecules lie within the phospholipid layer, providing hydrophilic channels through which inorganic ions may enter and leave the cell.
C) Only the second statement is true.
The lipid layer of the plasma membrane is made up of two rows of phospholipid molecules arranged so that their hydrophobic ends are in contact with each other and their polar ends are in contact with the protein layers.
Carbohydrate molecules which are attached to the outside of the plasma membrane, and are linked to the proteins or the lipids
B) Glycocalyx
Glycocalyx is also known as the cell coat.
True or False: The permeability of the membrane to K+ ions is much greater than that to the Na+ ions; thus, the passive efflux of K+ is much greater than the influx of Na+.
True
This results in a steady potential difference of about -80 mV, which can be measured across the plasma membrane since the inside of the membrane is negative with respect to the outside.
Which of the following is not true about the action potential?
C) Should multiple excitatory stimuli be applied to the surface of a neuron, then the effect can potentiated.
Should multiple excitatory stimuli be applied to the surface of a neuron, then the effect can summated.
True or False: The sodium and potassium channels, through which the sodium and potassium ions diffuse through the plasma membrane, are formed of lipid molecules that extend through the full thickness of the plasma membrane.
False
The sodium and potassium channels, through which the sodium and potassium ions diffuse through the plasma membrane, are formed of protein molecules that extend through the full thickness of the plasma membrane.
True or False: The selectivity of ion channels is based on the diameter of ions which passes through it.
False
The selectivity of ion channels cannot be due to the diameter of ions, since the K+ ion is larger than the Na+ ion. The movement of ions in solutions depends not only on the size of the ions, but also on the size of the shell of water surrounding it. K+ ions have weaker electric fields than Na+ ions; thus, K+ ions attract less water and act as if they are smaller than Na+ ions.
Gating may involve twisting and distortion of the channel, thus creating a wider or narrower lumen. Gating occur in response to stimuli such as voltage change, presence of ligand, or stretch or pressure.
B) Both statements are true.
Which of the following is incorrect about dendrites?
D) Later in life, they increase in number and size in response to altered functional demand from afferent axons.
During early embryonic development, there is an overproduction of dendrites. Later, they are reduced in number and size in response to altered functional demand from afferent axons.
All of the following are correct about axons, except:
B) The distal ends of their terminal branches are often enlarged and are called spines.
The distal ends of their terminal branches are often enlarged and are called terminals.
They usually do not branch close to the cell body; collateral branches may occur along their length.
True or False: Axoplasm differs from the cytoplasm of the cell body because it does not possess Nissl granules or Golgi complexes.
True
The sites for protein production, namely RNA and ribosomes, are absent. Thus, axonal survival depends on the transport of substances from the cell bodies.
Which of the following is not true about the initial segment of the axon?
A) It is the first 25-50 µm after it leaves the axon hillock of the nerve cell body.
It is the first 50-100 µm after it leaves the axon hillock of the nerve cell body.
True or False: The axons of posterior root ganglion cells carry impulses away from the cell body.
False
An axon always conducts impulses away from the cell body; but, the axons of posterior root ganglion cells are an exception. Here, the long neurite, which is indistinguishable from an axon, carries the impulse toward the cell body. (Recall unipolar neurons)
True or False: Worn-out organelles can be returned to the cell body for breakdown by the lysosomes via anterograde transport.
False
Worn-out organelles can be returned to the cell body for breakdown by the lysosomes via retrograde transport.
Which of the following is incorrect about synapses?
A) Under physiologic conditions, communication at a synapse can take place in both directions.
Under physiologic conditions, communication at a synapse can take place in only one direction.
When the receptor proteins on the postsynaptic membrane bind to the neurotransmitter, they undergo immediate conformation change that opens the ion channel. Generation of immediate but brief excitatory postsynaptic potential occurs with acetylcholine (muscarinic) and glutamate, while generation of inhibitory potential occurs with GABA.
D) Only the first statement is true.
Generation of immediate but brief excitatory postsynaptic potential occurs with acetylcholine (nicotinic) and glutamate.
Which of the following is not true about neuromodulators?
A) None of these
Examples of neuromodulators and acetylcholine (muscarinic), serotonin histamine, neuropeptides, and adenosine.
Which of the following is incorrect about electrical synapses?
A) They only allow unidirectional flow of nerve impulses.
Electrical synapses are bidirectional; chemical synapses are not.
Which of the following is not a characteristic of neuroglia?
A) Outnumbered by neurons
Neuroglia outnumber neurons by five to ten times and they compromise about half the total volume of the brain and spinal cord.
What are the four types of neuroglial cells?
OAME
Oligodendrocytes
Astrocytes
Microglia
Ependyma
Protoplasmic astrocytes are found mainly in the white matter, where their processes pass between nerve fibers. Meanwhile, fibrous astrocytes are found mainly in the gray matter, where their processes pass between nerve cell bodies.
D) Both statements are false.
Fibrous astrocytes are found mainly in the white matter, where their processes pass between nerve fibers. Meanwhile, protoplasmic astrocytes are found mainly in the gray matter, where their processes pass between nerve cell bodies.
Which of the following is not a characteristic of fibrous astrocytes?
D) None of these
Which of the following is not a characteristic of protoplasmic astrocytes?
D) They contain more filaments in their cytoplasm.
The cytoplasm of protoplasmic astrocytes contain fewer filaments than that of fibrous astrocytes.
Large number of oligodendritic processes are interwoven at the outer and inner surfaces of the central nervous system, where they form the outer and inner glial limiting membranes. The outer glial limiting membrane is beneath the pia mater, and the inner glial limiting membrane is beneath the ependyma lining the ventricles of the brain and the central canal of the spinal cord.
D) Only the second statement is true.
Large number of astrocytic processes are interwoven at the outer and inner surfaces of the central nervous system, where they form the outer and inner glial limiting membranes.
All of the following are functions of astrocytes, except:
B) They take up Na+ ions.
They take up K+ ions.
Other functions of astrocytes include: store glycogen, provide supporting framework, act as conduit for metabolites of raw materials, phagocytose, and produce trophic substances.
Oligodendrocytes are frequently found in rows along myelinated nerve fibers and surround nerve cell bodies. They are responsible for the formation of myelin sheath of nerve fibers in the peripheral nervous system.
D) Only the first statement is true.
They are responsible for the formation of myelin sheath of nerve fibers in the central nervous system.
Oligodendrocytes have only few processes, unlike Schwann cells. In addition, oligodendrocytes and their associated axons are not surrounded by a basement membrane.
A) Only the second statement is true.
Because oligodendrocytes have several processes, unlike Schwann cells, they can each form several internodal segments of myelin on the same or different axons. A single oligodendrocyte can form as many as 60 internodal segments.
Which of the following does not describe microglia?
D) It is embryologically related to the other neuroglial cells.
It is embryologically unrelated to the other neuroglial cells and are derived from macrophages outside the nervous system. These macrophages migrate into the nervous system during fetal life.
All of the following are true about the function of microglia, except:
C) In the presence of inflammatory disease of the CNS, they project their processes and migrate to the site of the lesion.
In the presence of inflammatory disease of the CNS, they retract their processes and migrate to the site of the lesion.
Ependymal cells which line the ventricles of the brain and the central canal of the spinal cord and play a role in CSF circulation and absorption
C) Ependymocytes
Ependymocytes form a single layer of cells that are cuboidal or columnar in shape and possess microvilli and cilia.
Ependymal cells which line the floor of the third ventricle and transport substances from CSF to hypophyseal-portal system
D) Tanycytes
Tanycytes have long basal processes that pass between the cells of the median eminence and place end feet on blood capillaries. These cells may play a part in the control of hormone production by the anterior pituitary gland.
True or False: Choroidal epithelial cells are held together by tight junctions to prevent leakage of CSF into the underlying tissues.
True
Choroidal epithelial cells are involved in production and secretion of CSF from the choroid plexus.
The extracellular space is in almost direct continuity with CSF in the subdural space externally and with CSF in the ventricles of the brain and in the central canal of the spinal cord internally. Thus, the extracellular space provides a pathway for exchange of ions and molecules between the blood and the neurons and glial cells.
D) Only the second statement is true.
The extracellular space is in almost direct continuity with CSF in the subarachnoid space externally...
The following diseases are spread through axonal transport, except:
A) Cytomegalovirus
The following statements concern the cytology of a neuron:
B) The protein molecules that extend through the full thickness of the plasma membrane of a neuron serve as sodium and potassium channels.
The gates of sodium and potassium channels are formed of protein molecules, not actin molecules.
The large size of the nucleolus in a neuron is related to the very large cytoplasm possessed by certain neurons.
A synapse is the site where two neurons come into proximity and where functional interneuronal communication occurs.
The following statements concern the axon:
C) The action potential is produced by sudden influx of Na+ ions into the cytoplasm.
The nerve impulse generated by a neuron originates at the initial segment of an axon.
Following influx of Na+ ions in the production of the action potential, the permeability for Na+ ions ceases, and the permeability for K+ ions increases.
The spread of the action potential along the plasma membrane of the axon constitutes the nerve impulse.
The following statements concern a nerve impulse:
A) The axolemma is the site of nerve conduction.
Subthreshold stimuli, when applied to the surface of a neuron, can be summated.
The refractory period is the duration of non-excitable state of the plasma membrane following the passage of a wave of depolarization.
Inhibitory stimuli are believed to produce their effect by causing an influx of Cl- ions through the plasma membrane of the neuron.
The following statements concern the structure of a synapse:
B) Synapses may be axodendritic, axosomatic, or axoaxonic.
The subsynaptic web lies beneath the postsynaptic membrane.
The synaptic cleft measures about 20 nm.
The majority of neurons produce and release only one principal neurotransmitter at all their nerve endings.
The following statements concern a neuron:
A) Nerve fibers are the dendrites and axons of a neuron.
The volume of cytoplasm within the nerve cell body is often far less than the total volume of cytoplasm in the neurites.
Golgi type I neurons have very long axons.
Golgi type I neurons form the Purkinje cells of the cerebellar cortex.
The following statements concern the neuron organelles and inclusions:
C) Mitochondria are found in the dendrites and axons.
Centrioles are found in mature nerve cells, as well as immature dividing nerve cells.
The Nissl substance is absent from the axon hillock.
Microfilaments contain actin and probably assist in cell transport.
The following statements concern dendrites:
A) Dendritic spines are small projections of the plasma membrane that increase the receptor surface area of the dendrite
Most dendrites taper in width as they extend from the nerve cell body.
A dendrite conveys a nerve impulse toward the nerve cell body.
The cytoplasm of dendrites contains ribosomes and agranular endoplasmic reticulum, as well as Nissl granules, microtubules, and microfilaments.
The following statements concern neuromodulators:
C) Neuromodulators may co-exist with the principal neurotransmitter at a single synapse.
They often enhance and prolong the effect of the principal neurotransmitter.
They may have a prolonged effect on the postsynaptic membrane.
Acetycholine (muscarinic) is a good example of a neuromodulator.
The following statements concern the neurobiology of neuron structures:
D) A receptor is a protein molecule on the postsynaptic membrane.
A terminal bouton is the presynaptic part of an axon.
Nissl substance is formed of the rough-surfaced endoplasmic reticulum.
Microtubules provide a stationary track that allows specific organelles to move by molecular motors.
The following statements concern neuroglia:
D) Replacement gliosis follows the death of neurons in the central nervous system and is due to proliferation of astrocytes.
Astrocytes are involved in the absorption of GABA secreted by the nerve terminals.
Fibrous astrocytes are locate mainly in the white matter of the central nervous system.
Unlike Schwann cells in the peripheral nervous system, a single oligodendrocyte can form, by means of its many processes, several internodal segments of myelin on the same or different axons.
The following statements concern the microglial cells:
A) In degenerative lesions of the central nervous system, the circulating blood contributes cells to the population of microglial cells.
Microglial cells migrate into the central nervous system during fetal life.
In the presence of damaged neurons, microglial cells round off and lose their branches and increase in number.
The following statements concern the ependymal cells:
C) Ependymal cells form a single layer, and many possess microvilli and cilia.
The ependymocytes line the ventricular system, but permit the cerebrospinal fluid to enter the extracellular spaces of the nervous tissue.
Tanycytes have long, branching basal processes, many of which have end feet place on the capillaries of the median eminence.
Through their microvilli, ependymal cells can absorb substances from the cerebrospinal fluid.
The following statements concern the extracellular space:
B) The space is in almost direct continuity with the subarachnoid space.
The extracellular space is formed by the gaps between the neurons and the neuroglial cells.
The extracellular space is continuous with the synaptic cleft between two neurons.
There are no lymphatic vessels within the central nervous system.
The following statements concern tumors of neuroglia:
C) They form about 40-50% of all intracranial tumors
Neuroglial tumors, apart from ependymomas, are highly malignant and difficult to remove surgically.
Neuroglial tumors commonly infiltrate between neurons, initially causing minimum disturbance of function; later, they completely disrupt neuronal activities.
Apart of ependymomas, neuroglial tumors are highly invasive.
The following statements concern neuroglial cells:
B) Heat reduces action potential in an axon and accentuates the signs and symptoms in multiple sclerosis.
Neuroglial cells tend to be smaller than nerve cell bodies.
Unlike Schwann cells, oligodendrocytes are not surrounded by a basement membrane.
Oligodendrocytes are found close to nerve cell bodies and their neurites.
The following statements concern the neuroglial cells:
D) The astrocytes form a scaffold for developing neurons.
Macroglia is the collective term used to describe astrocytes and oligodendrocytes as distinct from the smaller microglial cells.
The microglial cells have wavy processes with spine-like projections.
Oligodendrocyte processes are continuous with the myelin sheaths.
The myelin sheath is not part of the neuron but is formed by a supporting cell. In the central nervous system, the supporting cell is called Schwann cell; in the peripheral nervous system, it is called oligodendrocyte.
A) Only the first statement is true.
In the central nervous system, the supporting cell is called oligodendrocyte; in the peripheral nervous system, it is called Schwann cell.
Which of the following is not true about the myelin sheath?
A) It is segmented, discontinuous layer interrupted at irregular intervals by the nodes of Ranvier.
It is segmented, discontinuous layer interrupted at regular intervals by the nodes of Ranvier.
Rods and cones of the eye
B) Electromagnetic receptors
The rods and cones of the eyes are sensitive to changes in light intensity and wavelength.
Which of the following is incorrect about free nerve endings?
B) Their terminal endings contains myelin sheath.
Their terminal endings are devoid of myelin sheath, and there are no Schwann cells covering their tips.
The following statements describe Merkel discs, except:
A) They are fast adapting touch receptors.
Merkel discs are slowly adapting touch receptors that transmit information about the degree of pressure exerted in the skin, such as when one is holding a pen.
Bending of the hair stimulates the hair follicle receptors, which belong to the slowly adapting group of mechanoreceptors. While the hair remains bent, the receptor is silent, but when the hair is released, a further burst of nerve impulses is initiated.
B) Only the second statement is true.
Bending of the hair stimulates the hair follicle receptors, which belong to the rapidly adapting group of mechanoreceptors.
All of the following are non-encapsulated receptors, except:
C) Meissner's corpuscles
Meissner's, Pacinian, and Ruffini corpuscles are encapsulated receptors.
Meissner's corpuscles are found in
B) All of these
Meissner's corpuscles are very sensitive to touch and are rapidly adapting mechanoreceptors. They are also responsible for two-point tactile discrimination.
D) Both statements are true.
There are two types of sensory innervation of muscle spindles: the annulospiral and the flower spray. The annulospiral endings innervate the nuclear bag fibers, while the flower spray endings innervate the nuclear chain fibers.
A) Only the first statement is true
The annulospiral endings innervate both the nuclear bag and chain fibers, while the flower spray endings innervate the nuclear chain fibers.
Motor innervation of the intrafusal fibers is provided by fine alpha motor fibers. The nerves terminate in small motor end-plates situated at both ends of the intrafusal fibers.
C) Only the second statement is true.
Motor innervation of the intrafusal fibers is provided by fine gamma motor fibers. Stimulation of motor nerves causes both ends of the intrafusal fibers to contract and activate the sensory endings.
Nuclear chain fibers are concerned with dynamic responses and are associated with position and velocity of contraction. Meanwhile, nuclear bag fibers are associated with slow static contractions of voluntary muscle.
B) Both statements are false.
Nuclear bag fibers are concerned with dynamic responses and are associated with position and velocity of contraction. Meanwhile, nuclear chain fibers are associated with slow static contractions of voluntary muscle.
Which of the following does not describe neuropraxia?
B) Most common cause is traction.
Most common cause is pressure.
In neurotmesis, the proximal muscles will recover first, and the distal muscles will recover later. The muscles may respond to galvanic stimulation before voluntary control returns.
A) Only the first statement is true.
The muscles may respond to faradic stimulation before voluntary control returns.
Sensory recovery occurs before there is a return of voluntary movement. The part of the nerve distal to the section becomes very sensitive to mechanical stimulation once the regenerating sensory axons have entered the distal segment.
A) Both statements are true.
Simple tapping of the distal nerve trunk gives rise to a tingling sensation in the area of cutaneous distribution of the nerve. This sign is referred to as the Tinel sign.
Nervous tracts are bundles of nerve fibers found in the brain and spinal cord, most of which are myelinated. The following are the main structural differences between a myelinated nerve tract and a myelinated peripheral nerve fiber, except:
D) A nerve tract has Schmidt-Lanterman incisures, whereas a peripheral nerve does not.
Both nerve tract and peripheral nerve fiber have Schmidt-Lanterman incisures.
True or False: To treat residual Bell's palsy, section the vagus nerve behind and below the angle of the mandible is sectioned and anastomose its proximal end to the distal end of the facial nerve.
False
To treat residual Bell's palsy, section the hypoglossal nerve behind and below the angle of the mandible is sectioned and anastomose its proximal end to the distal end of the facial nerve. Although the right half of the tongue would be paralyzed, this causes little disability.
True or False: Tetanus toxin passes from a wound to the central nervous system through the spaces between nerve fascicles.
False
Tetanus toxin passes from a wound to the central nervous system through the spaces between individual nerve fibers.
Lidocaine is a local anesthetic that blocks nerve conduction by reducing permeability of axolemma to ions. The large diameter pain fibers are more susceptible to the action of this drug.
B) Only the first statement is true.
The small diameter pain fibers are more susceptible to the action of this drug.
True or False: The only receptors present in the cornea are free nerve endings.
True
In addition to pain, the cornea is sensitive to touch and temperature changes.
The following statements concern nerves:
C) Oligodendrocyte is the supporting cell of a myelinated nerve fiber in the central nervous system.
A nerve tract refers to a nerve fiber in the central nervous system.
A node of Ranvier in peripheral nerves is where two Schwann cells terminate and the plasma of the axon is exposed.
The major dense line of myelin consists of two inner protein layers of the plasma membrane that are fused together.
The following statements concern nerves:
B) The node of Ranvier is the site of nerve activity.
The minor dense line is made up of lipid.
As many as 15 or more unmyelinated axons may share a single Schwann cell in the peripheral nervous system.
Chromatolysis refers to the changes in the arrangement of Nissl material within the cytoplasm of the nerve cell body following injury.
The following statements concern oligodendrocyte:
B) A single oligodendrocyte may be associated with the myelin sheaths of as many as 60 axons.
The incisures of Schmidt-Lanterman are present in the myelinated fibers of the central nervous system.
Myelination in the central nervous system occurs by growth in length of the oligodendrocytic process and the wrapping of it around the axon.
A nonmyelinated axon in the central nervous system has no special relationship with the oligodendrocyte.
The following statements concern spinal nerves:
C) They are formed by the union of anterior and posterior nerve roots.
The posterior ramus of a spinal nerve contains both motor and sensory axons.
The anterior root of a spinal nerve contains only motor axons.
The posterior root ganglion of a spinal nerve contains unipolar neurons enveloped in capsular cells.
The following statements concern peripheral nerve plexuses:
B) A plexus is situated at the root of a limb permits nerve fibers from different segments of the spinal cord to become rearranged so that they more easily travel to different parts of the limb.
In peripheral nerve plexuses, bundles of nerve fibers branch, but in most instances, the individual nerve fibers do not branch.
The nerve plexuses of the autonomic nervous system possess a network of nerve fibers and nerve cells.
The peripheral nerve plexuses at the root of the limbs are formed from the anterior rami of the spinal nerves.
The following statements concern nerve conduction:
D) A typical action potential is about +40 mV.
In nerve conduction, an adequate stimulus increases the permeability of the axolemma to Na+ ions at the point of stimulation.
As the action potential moves along the axon, the entry of Na+ ions into the axon ceases and the permeability of the plasma membrane to K+ ions increases.
In the resting unstimulated nerve fiber, the interior of the plasma membrane (axolemma) is negative to the exterior.
The following statements concern the propagation of a nerve impulse:
A) In nonmyelinated nerve fibers, the action potential occurs along the length of the fiber.
A myelinated nerve fiber can be stimulated only at the nodes of Ranvier.
Saltatory conduction occurs in both peripheral and central nervous systems.
At the node of Ranvier, the action potential sets up an electric current in the surrounding tissue fluid.
The following statements concern wallerian degeneration:
D) The myelin breaks down into droplets that are phagocytosed by Schwann cells.
The Schwann cells can proliferate rapidly and become arranged in parallel cords within the persistent basement membrane.
In the central nervous system, the debris is removed by the microglial cells.
In the peripheral nervous system, the tissue macrophages are very active in removing nerve fragments.
The following statements concern the failure of regeneration of nerve fibers in the central nervous system:
A) Oligodendrocytes fail to multiply and form a band fiber, as do Schwann cells in the peripheral nervous system.
Endoneurial tubes are absent.
There are no nerve growth factors present.
The blood supply to the central nervous tissue is usually adequate.
The following factor may explain the partial return of function following injury to the spinal cord:
B) With training, the patient may use other muscles to compensate for the loss of paralyzed muscles.
An increase in the number of receptor sites may occur on the postsynaptic membranes and be responsible for some posttraumatic improvement.
There is no evidence that destroyed axons in the central nervous system completely regenerate after injury.
The edema fluid usually subsides at the site of injury and will result in some clinical improvement.
The following statements concern receptor endings:
B) Free nerve endings have no Schwann cells covering their tips.
Merkel discs are slow-adapting touch receptors.
The rods and cones of the eyes are electromagnetic receptors.
The taste and smell endings are chemoreceptors.
The following statements concern receptor endings:
C) There is a considerable reduction in the number of Meissner's corpuscles between birth and old age.
Ruffini corpuscles are slow-adapting stretch receptors found in the dermis of hairy skin.
Each pacinian corpuscle has a lamellated capsule and a central core containing the nerve ending.
The annulospiral endings in skeletal muscle possess intrafusal muscle fibers.
The following statements concern the cutaneous receptors:
D) The type of sensation felt is determined by the specific area of the central nervous system to which the sensory nerve fiber passes.
Transduction at the receptor is the process by which the energy of the stimulus is changed into electrochemical energy of the nerve impulse.
When applied to the receptor, the stimulus brings about a change in the potential of plasma membrane of the nerve ending.
Although there are a variety of histologic types of receptors, their nerves only transmit the same nerve impulses.
The following statements concern the function of a neuromuscular spindle:
B) It keeps the central nervous system informed about muscle activity.
It indirectly influences the control of voluntary movement.
It gives rise to afferent nerve impulses all the time.
When active or passive muscle movement occurs, there is an increase in the rate of passage of nerve impulses in the afferent nerve fibers.
The following statements concern the neurotendinous spindles:
C) They are found in fast- and slow-acting muscles.
They are situated in tendons close to the musculotendinous junction.
The nerve ends within the spindle by branching and terminating in club-shaped endings.
They are activated by changes in muscle tension and inhibits muscle contraction.
The following statements concern the neuromuscular junctions in skeletal muscle:
D) Each axon lies in a groove on the surface of the muscle fiber formed by the infolding of the muscle plasma membrane (sarcolemma).
At a neuromuscular junction each terminal branch of the motor nerve ends as a naked axon.
Having caused depolarization of the postsynaptic membrane, the acetylcholine is immediately hydrolyzed in the synaptic cleft by acetylcholinesterase.
Acetylcholine is released from the axon terminal when the nerve impulse reaches the neuromuscular junction.
The following statements concern the neuromuscular junctions on smooth and cardiac muscle:
C) The autonomic nerve fibers terminate on smooth muscle as unmyelinated fibers.
In smooth muscles, the autonomic nerve fiber exerts control over several muscle fibers. The wave of contraction passes from one muscle fiber to another by means of gap junctions.
In cardiac muscles, the wave of contraction spreads rapidly from one muscle to another by way of desmosomes and gap junctions.
At the site of neuromuscular junction, the axon lies in a shallow groove on the muscle surface, and the Schwann cell is retracted to expose the axolemma.
The following statements concern skin sensations and dermatomes:
B) To produce a region of complete anesthesia on the trunk, at least three segments of the spinal cord have to be damaged.
When contiguous spinal nerves are sectioned, the area of tactile loss is always greater than the area of loss of painful and thermal sensations.
The dermatome present on the medial side of the wrist is C8.
The dermatomes for the limbs run almost vertically.
The following statements concern muscle reflexes:
B) The biceps brachii tendon reflex involves the C5-6 segments of the spinal cord.
The patellar tendon reflex involves the L2-4 segments of the spinal cord.
A tumor pressing on the S1-2 segments of the spinal cord is likely interfere with the ankle jerk.
The abdominal superficial reflexes involve T6-T12 segments of the spinal cord.
The following statements concern the dermatomes of the trunk and lower limbs:
B) The L1 dermatome lies over the inguinal ligament.
The L5 dermatomes lies over the anterior and lateral surfaces of the leg below the knee.
The L2 dermatomes lies over the anterior and lateral surfaces of the thigh.
The S2 dermatome extends down the middle of the posterior surface of thigh and leg.
The following statements concern muscle innervation:
A) Muscle tone is dependent on the integrity of a simple monosynaptic reflex arc.
A motor unit consists of a motor neuron in the anterior gray column (horn) of the spinal cord and all the muscle fibers it supplies.
In the small muscles of the hand, one nerve fiber supplies only a few muscle fibers.
Neurotendinous spindles are innervated by myelinated nerve fibers.
The following statements concern skeletal muscle action:
B) When a prime mover contracts, the antagonistic muscles are inhibited.
When a muscle begins to contract, the smaller motor units are stimulated first.
Muscle fatigue is caused by a reduction in the amounts of ATP within the muscle fibers.
When a muscle is paralyzed, it immediately loses its normal tone.
The following statements concern posture:
B) In the standing position, the line of gravity passes through the odontoid process of the axis, behind the centers of the hip joints, and in front of the knee and ankle joints.
Posture depends on the degree and distribution of muscle tone.
A particular posture can often be maintained for long periods by different groups of muscle fibers in a muscle contracting in relays.
Nerve impulses arising in the eyes and ears can greatly influence posture.
The following clinical observation on muscle activity can be made:
A) Muscle wasting can occur if only the efferent motor nerve fibers to a muscle are sectioned.
Muscle fasciculation is seen with chronic disease that affects the anterior horn cells or the motor nuclei of cranial nerves.
Muscle contracture is a condition in which the muscle contracts and undergoes permanent shortening; it occurs frequently in muscles that normally oppose paralyzed muscles.
Wasting occurs in the muscles acting on the shoulder joint in patients with painful pericapsulitis involving that joint.
The nucleus pulposus in the young is an ovoid mass of cartilaginous material. It is normally under pressure and is situated slightly nearer to the posterior than to the anterior margin of the disc.
B) Only the second statement is true.
The nucleus pulposus in the young is an ovoid mass of gelatinous material.
An sudden increase in the compression load on the vertebral column causes the nucleus pulposus to become flattened, and this is accommodated by the resilience of the surrounding annulus fibrosus. Sometimes, the outward thrust it too great for the annulus fibrosus and it ruptures, allowing the nucleus pulposus to herniate and protrude into the vertebral canal.
B) Both statements are true.
The herniated nucleus pulposus may press on the spinal nerve roots, the spinal nerves, or even the spinal cord.
With advancing age, the nucleus pulposus becomes smaller and is replaced by hyaline cartilage. The collagen fibers of the annulus degenerate, so it cannot always contain the nucleus pulposus under stress.
B) Only the second statement is true.
With advancing age, the nucleus pulposus becomes smaller and is replaced by fibrocartilage.
True or False: In old age, it is no longer possible to distinguish the nucleus from the annulus.
True
True or False: In the cervical region, the supraspinous and interspinous ligaments are greatly thickened to form the strong posterior atlanto-occipital membrane.
False
In the cervical region, the supraspinous and interspinous ligaments are greatly thickened to form the strong ligamentum nuchae.
Which of the following is not true about the spinal cord?
C) It is relatively shorter in young children.
It is relatively longer in young children and usually ends at the upper border of the third lumbar vertebra.
It possesses a deep longitudinal fissure anteriorly (anterior median fissure) and a shallow furrow posteriorly (posterior median sulcus).
The amount of gray matter present at any given level of the spinal cord is related to the amount of muscle innervated at that level. Thus, its size is greatest within the cervical and lumbosacral enlargements of the spinal cord.
B) Both statements are true.
The central group of the anterior gray column is present in most segments of the spinal cord. It is responsible for innervating the skeletal muscles of the neck and trunk, including the intercostal and abdominal musculature.
B) Both statements are false.
The medial group of the anterior gray column is present in most segments of the spinal cord. It is responsible for innervating the skeletal muscles of the neck and trunk, including the intercostal and abdominal musculature.
True or False: The lateral group of the anterior gray column innervates the skeletal muscles of the limbs.
True
The lateral group is present in the cervical and lumbosacral segments of the cord.
Which of the following is not true about the cervical region of the spinal cord?
A) It has a round shape.
It has an oval shape.
Which of the following is not true about the thoracic region of the spinal cord?
B) Fasciculus cuneatus is only present in T1-T8 segments.
Fasciculus cuneatus is only present in T1-T6 segments, whereas fasciculus gracilis in present all throughout.
The posterior gray column contains the four nerve cell groups:
1. Substantia gelatinosa (present throughout the spinal cord)
2. Nucleus proprius (present throughout the spinal cord)
3. Nucleus dorsalis (present from C8 to L3-4 segments)
4. Visceral afferent nucleus (present from T1-L3 segments)
Which of the following is not true about the lumbar region of the spinal cord?
B) Its lateral gray column is only present in L3-L4 segments and gives rise to preganglionic sympathetic fibers.
Its lateral gray column is only present in L1-2 [3] segments.
Which of the following is not true about the sacral region of the spinal cord?
C) Its posterior gray column contains substance gelatinosa and nucleus dorsalis.
Its posterior gray column contains substance gelatinosa and nucleus proprius.
Which of the following is not true about substantia gelatinosa?
C) It constitutes the main bulk of cells present in the posterior gray column.
Nucleus proprius constitutes the main bulk of cells present in the posterior gray column.
The nucleus proprius is a group of large nerve cells situated anterior to the substantia gelatinosa throughout the spinal cord. It receives fibers from the posterior gray column that are associated with proprioception, two-point discrimination, and vibration.
C) Only the first statement is true.
It receives fibers from the posterior white column that are associated with proprioception, two-point discrimination, and vibration.
The nucleus dorsalis is a group of nerve cells situated at the apex of the posterior gray column, extending from C8 segment caudally to L3-4 segment. Most of the cells are comparatively large and are associated with neuromuscular and tendon spindles.
C) Only the second statement is true.
The nucleus dorsalis is a group of nerve cells situated at the base of the posterior gray column. The nucleus dorsalis is also known as Clarke's column.
The visceral afferent nucleus is a group of nerve cells of medium size situated medial to the nucleus dorsalis. It extends from T1-L3 segments and is associated with receiving visceral afferent information.
B) Only the second statement is true.
The visceral afferent nucleus is a group of nerve cells of medium size situated lateral to the nucleus dorsalis.
Superiorly, the spinal canal is continuous with the central canal of the rostral half of the medulla oblongata. Inferiorly in the conus medullaris, the spinal canal expands into the fusiform terminal ventricle.
D) Only the second statement is true.
Superiorly, the spinal canal is continuous with the central canal of the caudal half of the medulla oblongata. The rostral half of the medulla oblongata forms a part of the fourth ventricle.
True or False: In lateral spinothalamic tract, the fibers carrying pain are situated slightly anterior to those conducting temperature.
True
All of the following are part of the spinal lemniscus, except:
A) Dorsal spinocerebellar tract
All of the following chemical substances can stimulate the free nerve endings and cause pain, except:
D) Substance P
Serotonin, histamine, bradykinin, acids, and K+ ions can stimulate the free nerve endings. Meanwhile, prostaglandins and substance P cannot stimulate the free nerve endings directly by themselves; instead, they just lower the pain threshold for these endings.
The main excitatory neurotransmitter released by the A delta and C fibers is the amino acid acetylcholine. Substance P, a neuropeptide, is also released from the A delta fibers.
C) Both statements are false.
The main excitatory neurotransmitter released by the A delta and C fibers is the amino acid glutamate. Substance P, a neuropeptide, is also released from the C fibers.
True or False: Whereas substance P is a fast-acting localized neurotransmitter, glutamate has a slow release and diffuses widely in the posterior horn and can influence many neurons.
False
Whereas glutamate is a fast-acting localized neurotransmitter, substance P has a slow release and diffuses widely in the posterior horn and can influence many neurons.
The fast type of pain is precisely localized, whereas the slow type of pain is poorly localized. This may be because C fibers directly ascend the spinal cord in the lateral spinothalamic tract, whereas A delta fibers take part in multiple relays in the posterior gray horn before ascending to higher centers.
A) Only the first statement is true.
This may be because A delta fibers (fast pain) directly ascend the spinal cord in the lateral spinothalamic tract, whereas C fibers(slow pain) take part in multiple relays in the posterior gray horn before ascending to higher centers.
The following are sites concerned with reception and interpretation of nociceptive information, except?
D) Angular gyrus
The postcentral gyrus is involved with interpretation of pain in relation to past experiences.
The cingulate gyrus is involved with interpretation of the emotional aspect of pain.
The insular gyrus is involved with interpretation of pain stimuli from the internal organs and brings about an autonomic response.
All of the following are practical applications of gate control theory, except:
D) High-frequency ES
It should be low-frequency ES.
All of the following are neurotransmitter substance in the analgesic system of the brain, except:
B) Bradykinin
Enkephalins, endorphins, and serotonin may inhibit the release of substance P from the posterior gray column.
Which of the following is not true about the anterior spinothalamic tract?
D) As this tract ascends through the spinal cord, new fibers are added to the lateral aspect of it.
As this tract ascends through the spinal cord, new fibers are added to the medial aspect of it. Thus, in the upper cervical segments of the cord, the sacral fibers are mostly lateral and the cervical segments are mostly medial.
The fasciculus gracilis is present throughout the length of the spinal cord. Meanwhile, the fasciculus cuneatus is only present in the upper thoracic and cervical segments of the spinal cord.
C) Both statements are true.
The fasciculus cuneatus and gracilis are separated by a septum.
The fasciculus gracilis contains the long descending fibers from the sacral, lumbar, and lower six thoracic spinal nerves. Meanwhile, the fasciculus cuneatus contains the long descending fibers from the upper six thoracic and all cervical spinal nerves.
B) Both statements are false.
The fasciculus gracilis contains the long ascending fibers from the sacral, lumbar, and lower six thoracic spinal nerves. Meanwhile, the fasciculus cuneatus contains the long ascending fibers from the upper six thoracic and all cervical spinal nerves.
True or False: Spinocerebellar tract has a third-order neuron.
False
The third-order neuron is usually in the thalamus and gives rise to a projection fiber that passes to a sensory region of the cerebral cortex.
The axons of the second-order neurons in the anterior spinocerebellar tract ascend on the ipsilateral white column. The majority of the axons of the second-order neurons in the posterior spinocerebellar tract cross and ascend on the contralateral white column; whereas the minority of the axons ascend on the ipsilateral white column.
C) Both statements are false.
The axons of the second-order neurons in the posterior spinocerebellar tract ascend on the ipsilateral white column. The majority of the axons of the second-order neurons in the anterior spinocerebellar tract cross and ascend on the contralateral white column; whereas the minority of the axons ascend on the ipsilateral white column.
True or False: The axons of the second-order neurons in the anterior spinocerebellar tract that crossed over to the opposite side in the spinal cord cross back within the cerebrum.
False
The axons of the second-order neurons in the anterior spinocerebellar tract that crossed over to the opposite side in the spinal cord cross back within the cerebellum.
Which of the following is not true about the pain and temperature pathways?
A) Third-order neuron: ventral posteromedial nucleus of thalamus
It should be ventral posterolateral nucleus of thalamus.
Which of the following is not true about the light touch and pressure pathways?
B) Second-order neuron: nucleus proprius
It should be substantia gelatinosa.
Which of the following is not true about the muscle joint sense pathways?
C) Destination: cerebral cortex
It should be cerebellar cortex.
The spinotectal tract terminates by synapsing with the neurons in the inferior colliculus of the midbrain. This pathway provides efferent information for spinovisual reflexes and brings about movement of the eyes and head toward the source of the stimulation.
D) Both statements are false.
The spinotectal tract terminates by synapsing with the neurons in the superior colliculus of the midbrain. This pathway provides afferent information for spinovisual reflexes and brings about movement of the eyes and head toward the source of the stimulation.
True or False: The axon of the third-order neuron innervates the skeletal muscle through the anterior root and spinal nerve.
True
Third-order neuron is also known as the lower motor neuron.
About one-third of the fibers of corticospinal tract originate from the primary motor cortex, one-third originate from the secondary motor cortex, and one-third originate from the parietal lobe. Thus, one-third arise from the precentral gyrus, and two-thirds arise from the postcentral gyrus.
B) Only the first statement is true.
Thus, two-thirds arise from the precentral gyrus, and one-third arise from the postcentral gyrus.
True or False: Fibers of the corticospinal tract arise as axons of pyramidal cells situated in the fifth layer of the cerebral cortex.
True
The fibers of the anterior corticospinal tract do not cross in the medulla, but they eventually cross the midline and terminate in the anterior gray column of the spinal cord segments in the cervical and lower thoracic regions.
False
They eventually cross the midline and terminate in the anterior gray column of the spinal cord segments in the cervical and upper thoracic regions.
The reticulospinal fibers include the descending autonomic fibers. Thus, the reticulospinal tract provides a pathway by which the thalamus can control the sympathetic outflow and the sacral parasympathetic outflow.
A) Only the first statement is true.
The reticulospinal tract provides a pathway by which the hypothalamus can control the sympathetic outflow and the sacral parasympathetic outflow.
True or False: The red nucleus is situated in the tectum of the midbrain at the level of the superior colliculus.
False
The red nucleus is situated in the tegmentum of the midbrain at the level of the superior colliculus.
The vestibulospinal tract facilitates the activity of the flexor muscles and inhibits the activity of the extensor muscles. Meanwhile, the rubrospinal tract facilitates that activity of the extensor muscles and inhibits the activity of the flexor muscles.
B) Both statements are false.
The rubrospinal tract facilitates the activity of the flexor muscles and inhibits the activity of the extensor muscles. Meanwhile, the vestibulospinal tract facilitates that activity of the extensor muscles and inhibits the activity of the flexor muscles.
Which of the following is incorrect about corticospinal tracts?
A) They are responsible for the rapid, skilled, voluntary movements, especially the proximal parts of the limbs.
They are responsible for the rapid, skilled, voluntary movements, especially the distal ends of the limbs.
All of the following are true about tectospinal tract, except:
A) It originates from inferior colliculus.
It originates from superior colliculus.
In its simplest form, a reflex arc consists of the following anatomical structures, except:
A) Afferent organ
It should be receptor organ.
True or False: According to the law of reciprocal innervation, flexors and extensor reflexes of the same limb cannot be made to contract simultaneously.
True
True or False: The spinal cord is held in position by the denticulate ligaments on each side and the conus medullaris inferiorly.
False
The spinal cord is held inferiorly by the filum terminale.
True or False: The subarachnoid space extends inferiorly beyond the end of the spinal cord and ends at the level of the lower border of the fourth sacral vertebra.
False
The subarachnoid space ends at the level of the lower border of the second sacral vertebra.
Because of the shortness of the spinal cord relative to the length of the vertebral column, the nerve roots of the lumbar and sacral segments have to take an oblique course downward to reach their respective intervertebral foramina. The resulting leash of nerve roots forms the:
C) Cauda equina
Within the anterolateral white column of the spinal cord, the axons of from the sacral and lumbar segments of the body are deflected laterally by axons crossing the midline at successively higher levels. Within the posterior white column, the axons from the sacral and lumbar segments of the body are pushed medially by the axons from the higher segments of the body.
A) Both statements are true.
This deflection of the tracts produces lamination; thus, in the spinothalamic tracts (anterolateral system), the cervical to sacral segments are located from medial to lateral, whereas in the posterior white column (medial lemniscus system), the sacral to cervical segments are located from medial to lateral.
All of the following are manifestations of tabes dorsalis, except:
A) Hyposensitivity of skin to touch, heat, and cold
It should be hypersensitivity of skin to touch, heat, and cold.
True or False: Muscle is independent on the integrity of a monosynaptic reflex arc.
False
Muscle tone is a state of continuous partial contraction of a muscle and is dependent on the integrity of a monosynaptic reflex arc. The receptor organs are the muscle spindles. The afferent neuron enters the spinal cord through the posterior root and synapses with the effector neuron or lower motor neuron in the anterior gray column. The lower motor neuron supplies the muscle fibers by travelling through the anterior roots, the spinal nerves, and the peripheral nerves.
True or False: Muscle spindles are excitatory to muscle tone, whereas neurotendinous receptors are inhibitory to muscle tone.
True
True or False: Basal ganglia and cerebellum greatly influence voluntary movements even though they do not give rise directly to descending tracts that influence the activities of the lower motor neuron.
True
Which of the following is not true about the Babinski sign?
D) It is normally present up until the second year of life.
Babinski sign is normally present during the first year of life because the corticospinal tract is not myelinated until the end of the first year of life.
When a lower motor neuron is cut, a muscle will no longer respond to interrupted electrical stimulation 7 days after nerve section, although it sill will respond to direct current. After 10 days, the response to direct current ceases. This changes in muscle response to electrical stimulation is known as the:
Reaction of degeneration
Tremors may be slow, as in parkinsonism, or fast, as in thyrotoxicosis. They may occur at rest, as in parkinsonism, or with action, as in cerebral disease.
A) Only the first statement is true.
They may occur at rest, as in parkinsonism, or with action, as in cerebellar disease.
Myoclonus is a sudden contraction of an isolated muscle or part of a muscle. It may be present with diseases that involve the reticular formation and the cerebellum.
A) Both statements are true.
Normal myoclonic jerks sometimes occur in individuals as they are falling asleep and are believed to be due to a sudden temporary reactivation of the reticular formation.
True or False: Spinal shock, especially when the lesion is at a high level of the cord, may cause severe hypertension.
False
Spinal shock, especially when the lesion is at a high level of the cord, may cause severe hypotension from loss of sympathetic vasomotor tone.
Anal sphincter reflex can be tested by placing a gloved finger in the anal canal and stimulating the anal sphincter to contract by squeezing the glans penis or clitoris or gently tugging on an inserted Foley catheter. The presence of this reflex would indicate the existence of spinal shock.
A) Only the first statement is true.
The absence of this reflex would indicate the existence of spinal shock. However, a cord lesion involving the sacral segments would nullify this test, since the neurons giving rise to the inferior hemorrhoidal nerve to the anal sphincter (S2-4) would be nonfunctioning.
True or False: If there is a complete fracture dislocation at the L2-3 vertebral level, no cord injury occurs.
True
Neural damage is confined to the cauda equina, and lower motor neuron, autonomic, and sensory fibers are involved.
All of the following can cause anterior cord syndrome, except:
C) None of these
True or False: Radiographs of central cord syndrome often appear normal.
True
Radiographs of central cord syndrome often appear normal because no fracture or dislocation has occurred.
True or False: In central cord syndrome, there is bilateral spastic paralysis below the level of the lesion with characteristic sacral "sparing".
True
In central cord syndrome, the lower limb fibers are affected less than the upper limb fibers because the descending fibers in the lateral corticospinal tracts are laminated, with the upper limb fibers located medially and the lower limb fibers located laterally.
The sparing of the lower part of the body in the central cord syndrome may be evidenced by the following, except:
A) Ability to move feet slightly
It should be ability to move toes slightly.
All of the following are possible causes of hemisection of the spinal cord, except:
C) None of these
Hemisection of the spinal cord is also known as Brown-Sequard syndrome.
True or False: In Brown-Sequard syndrome, there is contralateral loss of pain and temperature sensations immediately below the level of the lesion.
False
Because the lateral spinothalamic tracts cross obliquely, the sensory loss occurs two or three segments below the lesion distally.
True or False: If the anterior spinothalamic tracts are damaged, there is a complete, contralateral loss of tactile sensation two or three segments below the level of the lesion.
False
If the anterior spinothalamic tracts are damaged, there is an incomplete, contralateral loss of tactile sensation two or three segments below the level of the lesion. The contralateral loss of tactile sense is incomplete because the discriminative touch travelling in the ascending tracts in the contralateral posterior white column remains intact.
Syringomyelia, which is due to a developmental abnormality in the formation of the central canal, most often affects the brainstem and thoracic region of the spinal cord. At the site of the lesion, there is cavitation and gliosis in the central region of the neuroaxis.
C) Only the second statement is true.
Syringomyelia most often affects the brainstem and cervical region of the spinal cord.
Which of the following is not a manifestation of syringomyelia?
C) None of these
Bilateral spastic paralysis of both legs may occur in syringomyelia, with exaggerated deep tendon reflexes and the presence of a positive Babinski response. These signs are produced by the further expansion of the lesion laterally into the white column to involve the descending tracts.
Other manifestations of syringomyelia include weakness of small muscles of the hand and Horner's syndrome.
True or False: In poliomyelitis, improvement usually begins at the end of the second week as the edema in the affected area subsides and function returns to the neurons that have not been destroyed.
False
In poliomyelitis, improvement usually begins at the end of the first week as the edema in the affected area subsides and function returns to the neurons that have not been destroyed.
True or False: In syringomyelia, one side of the body may be affected more than the other.
True
In syringomyelia, one side of the body may be affected more than the other secondary to the uneven growth of the cavitation.
True or False: Following spinal shock resolution, paraplegia in extension occurs due to the overactivity of the gamma efferent nerve fibers to the muscle spindles as a result of the release of these neurons from the higher centers.
True
Meanwhile, paraplegia in flexion occurs when all the descending tracts are severed.
The following statements concern the spinal cord:
C) The large nerve cell bodies in the anterior gray horns gives rise to the alpha efferent nerve fibers in the anterior roots.
The terminal ventricle is the expanded lower end of the central canal.
The substantia gelatinosa group of cells is located at the apex of each posterior gray column throughout the length of the spinal cord.
The anterior and posterior gray columns on the two sides of the spinal cord are united by a gray commissure.
The following statements concern the white columns of the spinal cord:
B) The anterior spinothalamic tract is found in the anterior white column.
The posterior spinocerebellar tract is situated in the lateral white column.
The fasciculus gracilis is found in the posterior white column.
The rubrospinal tract is found in the lateral white column.
The following statements concern the spinal cord:
A) The spinal cord has a cervical enlargement for the brachial plexus.
The spinal cord possesses spinal nerves that are attached to the cord by anterior and posterior nerve roots.
In the adult, the spinal cord usually ends inferiorly at the lower border of the first lumbar vertebra.
The ligamentum denticulatum anchors the spinal cord to the dura mater along each side.
The following statements concern the cell of origin of the tracts listed below:
C) The lateral spinothalamic tract arises from the cells in the substantia gelatinosa.
The fasciculus cuneatus and gracilis arises from the cells in the posterior root ganglion.
The anterior spinocerebellar tract arises from the cells in the nucleus dorsalis.
The following statements concern the courses taken by the tracts listed below:
B) The fasciculus gracilis does not cross to the opposite side of the neural axis.
The spinotectal tract crosses to the opposite side of the spinal cord.
The posterior spinocerebellar tract does not cross to the opposite side of the spinal cord.
The anterior spinothalamic tract crosses very obliquely to the opposite side of the spinal cord.
The following statements concern the nucleus of termination of the tracts listed below:
C) The anterior spinothalamic tract terminates in the ventral posterolateral nucleus of the thalamus.
The spinoreticular tract terminates on the neurons of the reticular formation in the medulla, pons, and midbrain.
The spinotectal tract terminates in the superior colliculus.
The anterior spinocerebellar tract terminates in the cerebellar cortex.
The following statements relate sensations with the appropriate nervous pathways:
A) Unconscious muscle joint sense travels in the anterior spinocerebellar tract.
Pain travels in the lateral spinothalamic tract.
Pressure travels in the anterior spinothalamic tract.
Vibration travels in the fasciculus gracilis, whereas two-point discrimination travels in the fasciculus cuneatus.
The following statements concern the gating theory of pain:
C) Massage applied to the skin over a painful joint may reduce pain sensitivity.
Stimulation of large non-pain conducting fibers in a peripheral nerve may reduce pain sensitivity.
Stimulation of A delta and C fibers in a posterior root of a spinal nerve may increase pain sensitivity.
Degeneration of large non-pain conducting fibers in a peripheral nerve increases pain sensitivity.
The following statements concern the reception of pain:
A) The slow-conducting C-type fibers are responsible for prolonged, burning pain.
Substance P, a peptide, is thought to be the neurotransmitter at the synapses where the first-order neuron terminates on the cells in the posterior gray column of the spinal cord.
The enkephalins and endorphins may serve to inhibit the release of substance P in the posterior gray column of the spinal cord.
Many of the tract conducting the initial, sharp, pricking pain terminate in the ventral posterolateral nucleus of the thalamus.
The following statements concern the corticospinal tracts:
A) They occupy the posterior limb of the internal capsule.
They arise as axons of the pyramidal cells in the fifth layer of the cerebral cortex.
Those that control movements of the upper limb originate in the precentral gyrus on the lateral side of the hemisphere.
Those that are concerned with the movements of the lower limb are located in the lateral area of the middle three-fifths of the basis pedunculi.
The following statements concern the course taken by the tracts listed below:
C) The anterior corticospinal tract crosses the midline in the spinal cord.
The rubrospinal tract crosses the midline of the neuroaxis in the midbrain.
The tectospinal tract (most of the nerve fibers) crosses the midline in the midbrain.
The vestibulospinal tract does not cross the midline and ascends through the medulla oblongata and spinal cord in the anterior white column.
The following statements concern the nerve cells of origin for the tracts listed below:
B) The lateral corticospinal tract originates from cells in area 4 of the cerebral cortex.
The vestibulospinal tract originates from cells of the lateral vestibular nucleus situated in the pons.
The rubrospinal tract originates from cells in the red nucleus.
The reticulospinal tract originates from cells in the reticular formation in the midbrain, pons, and medulla oblongata.
The following statements concern muscle movement:
C) Hyperactive ankle-jerk reflexes and ankle clonus indicate a release of the lower motor neurons from supraspinal inhibition.
Muscular fasciculation is seen only when there is slow destruction of the lower motor neurons.
Muscle spindle afferent nerve fibers send information to the brain as well as to the spinal cord.
Brain neuronal activity preceding a voluntary movement is not limited to the precentral gyrus (area 4).
After a hemorrhage into the left internal capsule in a right-handed person, the following sign or symptom may be present:
A) Right astereognosis
Following damage to the left internal capsule, there will be right homonymous hemianopsia, right hemiplegia, aphasia, and right-sided Babinski response.
A patient with traumatic lesion of the left half of the spinal cord at the level of the eighth cervical segment might present the following sign(s) and symptom(s):
A) Left positive Babinski sign
Left-sided lower motor paralysis in the segment of the lesion and muscular atrophy
Loss of pain and temperature sensations on the right side below the level of the lesion
Loss of position sense on the left leg
Which of the signs and symptoms listed below is indicative of a cerebellar lesion?
D) Intention tremor
Athetosis and chorea occur with lesions of the corpus striatum.
Cogwheel rigidity occurs in Parkinson disease.
Hemiballismus occurs with lesion of contralateral subthalamic nucleus.
Which of the following regions of the white matter would not contain corticospinal fibers?
C) Anterior limb of the internal capsule
It should be the posterior limb of the internal capsule. Pyramids of the medulla oblongate also contain corticospinal fibers.
A 59-year old woman was experiencing pain the back and showed evidence of loss of pain and temperature sensations down the back of her left leg. Radiographic examination of the vertebral column showed evidence of metastases in the bodies of the 9th and 10th thoracic vertebrae. The pain in the back of this patient could be explained by the following facts, except:
C) Spasms of the postvertebral muscles following pressure of the tumor on the posterior white columns of the spinal cord
Spasms of the postvertebral muscles would not be produced by pressure on the posterior white columns of the spinal cord.
The loss of pain and temperature sensations down the back of the patient's left leg in the area of S1-3 dermatomes could be explained by the following factual statements, except:
C) The loss of temperature sensations in the leg could be explained by pressure of the tumor on the anterior spinothalamic tract.
The sensation of temperature travels in the lateral spinothalamic tract along with the pain impulses.
The severe intractable pain in the back in a patient with cancer could be treated by the following methods, except:
C) The prescription of salicylates in large doses
Salicylates, such as aspirin, sodium salicylates, and diflunisal, are used clinically only for the relief of mild to moderate pain. Other treatment options for severe intractable pain include the direct injection of the opiate into the spinal cord and cordotomy.
The interior of the base of the skull is divided into three cranial fossae: anterior, middle, and posterior. The anterior cranial fossa is separated from the middle cranial fossa by the greater wing of the sphenoid, and the middle cranial fossa is separated from the posterior cranial fossa by the petrous part of the temporal bone.
A) Only the first statement is true.
The anterior cranial fossa is separated from the middle cranial fossa by the lesser wing of the sphenoid.
True or False: The anterior cranial fossa lodges the frontal lobes of the cerebral hemisphere, whereas the expanded lateral parts of the middle cranial fossa lodge the parietal lobes.
False
The expanded lateral parts of the middle cranial fossa lodge the temporal lobes.
The foramen ovale lies posterolateral to the foramen rotundum. It perforates the greater wing of the sphenoid and transmits the large sensory root and small motor root of the mandibular nerve to the infratemporal fossa.
D) Both statements are true.
The foramen spinosum lies posterolateral to the foramen rotundum and also perforates the greater wing of the sphenoid. This foramen transmits the anterior meningeal artery from the infratemporal fossa into the cranial cavity.
C) Both statements are false.
The foramen spinosum lies posterolateral to the foramen ovale and ittransmits the middle meningeal artery from the infratemporal fossa into the cranial cavity.
True or False: The posterior cranial fossa lodges the parts of the hindbrains, namely, the midbrain, pons, and medulla oblongata.
False
The posterior cranial fossa lodges the parts of the hindbrains, namely, the cerebellum, pons, and medulla oblongata.
The following structures pass through the foramen magnum, except:
B) Ascending cranial parts of the accessory nerves
It should be ascending spinal parts of the accessory nerves.
The following structures pass through the jugular foramen, except:
A) None of these
The inferior petrosal sinus and the sigmoid sinus also pass through the jugular foramen.
True or False: The maxilla is the largest and strongest bone of the face.
False
The mandible is the largest and strongest bone of the face.
All of the following are functions of the brainstem, except:
C) It contains the important nuclei of cranial nerves II through XII.
It should be cranial nerves III through XII.
Which of the following is not true about the medulla oblongata?
B) The junction of the medulla and spinal cord is at the origin of the anterior and posterior roots of the second cervical spinal nerve.
The junction of the medulla and spinal cord is at the origin of the anterior and posterior roots of the first cervical spinal nerve, which corresponds approximately to the level of the foramen magnum.
Lateral to the gracile tubercle is a similar swelling called the cuneate tubercle.
True or False: The decussation of the lemnisci takes place anterior to the central gray matter and posterior to the pyramids.
True
The pons connect the medulla oblongata to the midbrain. It also connects the right and left cerebral hemispheres.
C) Only the first statement is true.
It also connects the right and left cerebellar hemispheres.
True or False: In the groove between the pons and the medulla oblongata, there emerge, from medial to lateral, the abducent, facial, and vestibulocochlear nerves.
True
Which of the following is not true about the midbrains?
A) None of these
The four colliculi are also known as the corpora quadrigemina.
The midbrain comprises of two lateral halves, called the cerebral peduncles. Each cerebral peduncle is divided into an anterior part, the crus cerebri, and a posterior part, the tegmentum, by a pigmented band of gray matter, the substantia ferruginea.
A) Only the first statement is true.
Each cerebral peduncle is divided into anterior and posterior parts by a pigmented band of gray matter, the substantia nigra. Substantia ferruginea is a part of the pons.
The substantia nigra is a large sensory nucleus situated between the tegmentum and the crus cerebri and is found throughout the midbrain. The nucleus is composed of medium-sized multipolar neurons that possess inclusion granules of melanin pigment within their cytoplasm.
C) Only the second statement is true.
The substantia nigra is a large motor nucleus.
The crus cerebri contains important descending tracts. Which of the following statements below is not true?
A) None of these
All of the following are true about the superior colliculus, except:
B) It receives afferent fibers from the optic nerve, the visual cortex, and the tectospinal tract.
The superior colliculus receives afferent fibers from the optic nerve, the visual cortex, and the spinotectal tract. The efferent fibers form the tectospinal and tectobulbar tracts.
Downward herniation of the medulla and cerebellar tonsils through the foramen magnum may occur following an increase in the intracranial pressure. This will produce symptoms of headache, neck stiffness, and paralysis of glossopharyngeal, vagus, accessory, and hypoglossal nerves owing to traction.
C) Both statements are true.
True or False: In the presence of tonsillar herniation, it is extremely dangerous to perform a lumbar puncture.
True
It is extremely dangerous to perform a lumbar puncture because the sudden withdrawal of the cerebrospinal fluid may precipitate further herniation of the brain through the foramen magnum.
The Arnold-Chiari malformation is a congenital anomaly in which there is herniation of the cerebellar tonsils and the medulla oblongata through the foramen magnum into the vertebral canal. This results in the blockage of the exits in the roof of the third ventricle to the cerebrospinal fluid, causing internal hydrocephalus.
B) Only the first statement is true.
Arnold-Chiari malformation results in the blockage of the exits in the roof of the fourth ventricle to the cerebrospinal fluid. It is commonly associated with craniovertebral anomalies or various forms of spina bifida.
The following structures may be affected in Wallenburg syndrome, except:
B) Superior cerebellar peduncle
The lateral part of the medulla is supplied by the posterior inferior cerebellar artery, which is a branch of the vertebral artery. Thrombosis of either of these arteries produces the following signs and symptoms:
1. Dysphagia and dysarthria due to paralysis of ipsilateral palatal and laryngeal muscles (nucleus ambiguus)
2. Analgesia and thermoanesthesia on the ipsilateral side of the face (nucleus and spinal tract of the trigeminal nerve)
3. Vertigo, nausea, vomiting, and nystagmus (vestibular nuclei)
5. Ipsilateral gait and limb ataxia (cerebellum or inferior cerebellar peduncle)
6. Contralateral loss of sensations of pain and temperature (spinal lemniscus - spinothalamic tract)
All of the following structures may be affected in Dejerine-Sottas syndrome, except:
C) All of these
Thrombosis of the medullary branch of the vertebral artery results to Dejerine syndrome, which is characterized by the following signs and symptoms:
1. Contralateral hemiparesis (pyramidal tract)
2. Contralateral impaired sensations of position and movement and tactile discrimination (medial lemniscus)
3. Ipsilateral paralysis of tongue muscles with deviation to the paralyzed side when the tongue is protruded (hypoglossal nerve)
Astrocytoma of the pons occurring in childhood is the most common tumor of the brainstem. The signs and symptoms are those of ipsilateral cranial nerve paralysis and contralateral hemiparesis.
C) Both statements are true.
Astrocytoma of the pons may produce the following signs and symptoms:
1. Weakness of facial muscles on the same side (facial nerve nucleus)
2. Weakness of the lateral rectus muscle on one or both sides (abducent nerve nucleus)
3. Nystagmus (vestibular nucleus)
4. Weakness of jaw muscles (trigeminal nerve nucleus)
5. Hearing impairment (cochlear nuclei)
6. Contralateral hemiparesis or quadriparesis (corticospinal fibers)
7. Anesthesia to light touch with preservation of appreciation of pain over the skin of the face (principal sensory nucleus of trigeminal nerve involved, leaving the spinal nucleus and tract of trigeminal intact)
8. Contralateral sensory defects of trunk and limbs (medial and spinal lemnisci)
10. Impairment of conjugate deviation of eyeballs (medial longitudinal fasciculus, which connects the oculomotor, trochlear, and abducent nerve nuclei)
Which of the following is not true about pontine hemorrhage?
C) When the hemorrhage is extensive and bilateral, the pupils may be dilated.
When the hemorrhage is extensive and bilateral, the pupils may be "pinpoint" due to the involvement of the ocular sympathetic fibers. There is commonly bilateral paralysis of the face and the limbs. The patient may become poikilothermic because damage to the pons has cut off the body from the heat-regulating centers in the hypothalamus.
The following structures are found in the midbrain, except:
B) Locus coeruleus
Locus coeruleus is found in the pons. Oculomotor and trochlear nerves are also found in the midbrain.
Damage to the oculomotor nucleus following trauma to the midbrain will produce ipsilateral paralysis of levator palpebrae superioris; the superior, inferior, and medial rectus muscles; and the superior oblique muscle. Malfunction of the parasympathetic nucleus of the oculomotor nerve produces a dilated pupil that is insensitive to light and does not constrict on accommodation.
C) Only the second statement is true.
Damage to the oculomotor nucleus will produce ipsilateral paralysis of the inferior oblique muscle; whereas damage to the trochlear nucleus will produce ipsilateral paralysis of the superior oblique muscle.
All of the following are manifestations of Weber syndrome, except:
B) Ipsilateral hemiplegia
It should be contralateral hemiplegia.
True or False: Benedikt syndrome is similar to Weber syndrome, but the necrosis involves the medial lemniscus and red nucleus, producing contralateral hemianesthesia and involuntary movements of the limbs on the opposite side.
True
True or False: The cranial part of the accessory nerve is distributed within the glossopharyngeal nerve so that it is not possible to test for this nerve alone.
False
The cranial part of the accessory nerve is distributed within the vagus nerve.
The following cranial nerves are affected by lesions in the medulla oblongata, except:
B) Spinal accessory nerve
The spinal part of accessory nerve, which supplies the sternocleidomastoid and trapezius muscles, arises from the spinal cord and is therefore unaffected by lesions in the medulla.
True or False: Hydrocephalus is commonly associated with Arnold-Chiari malformation.
True
The hydrocephalus may be due to distortion or malformation of the openings in the roof of the fourth ventricle, which normally allow the cerebrospinal fluid to escape into the subarachnoid space.
All of the following cranial nerves emerge from the medulla oblongata in a groove between the olives and inferior cerebellar peduncles, except:
D) Hypoglossal
The 9th, 10th, and 11th (cranial part) nerves emerge from the medulla oblongata in a groove between the olives and the inferior cerebellar peduncles. The hypoglossal nerve emerges between the olives and the pyramids.
The following statements concern the anterior surface of the medulla oblongata:
C) The pyramids taper inferiorly and give rise to the decussation of the pyramids.
On each side of the midline on the anterior surface of the medulla lateral to the pyramids, there is an ovoid swelling called the olive, which contains the olivary nucleus.
The hypoglossal nerve emerges between the pyramid and the olive.
The vagus nerve emerges between the olive and the inferior cerebellar peduncle.
The following general statements concern the medulla oblongata:
D) The caudal half of the floor of the fourth ventricle is formed by the rostral half of the medulla.
The central canal in the medulla oblongata is limited to the caudal half.
The nucleus gracilis is situated beneath the gracile tubercle on the posterior surface of the medulla.
The decussation of the medial lemnisci takes place in the caudal half of the medulla.
The cerebellum lies posterior to the medulla.
The following statements concern the interior of the lower part of the medulla:
A) The internal arcuate fibers emerge from the nucleus gracilis and nucleus cuneatus.
The decussation of the pyramids represents the crossing over from one side of the medulla to the other of three-fourths of the corticospinal fibers.
The substantia gelatinosa is continuous with the nucleus of the spinal tract of the trigeminal nerve.
The medial lemniscus is formed by the axons of cells in thenucleus gracilisand the nucleus cuneatus; the axons leave the nuclei and cross the midline as the internal arcuate fibers and then ascend to the thalamus.
The following statements concern the interior of the upper part of the medulla:
A) Beneath the floor of the fourth ventricle are located the dorsal nucleus of the vagus and the vestibular nuclei.
The nucleus ambiguus constitutes the motor nucleus of the glossopharyngeal, vagus, and cranial part of the accessory nerves.
The medial longitudinal fasciculus is a bundle of ascending and descending fibers that lie posterior to the medial lemniscus on each side of the midline.
The inferior cerebellar peduncle connects the medulla to the cerebellum.
The following statements concern the Arnold-Chiari phenomenon:
C) The exits in the root of the fourth ventricle may be blocked.
The tonsil of the cerebellum may herniate through the foramen magnum.
It is dangerous to perform a spinal tap in this condition.
It is a congenital anomaly.
The following statements concern the medial medullary syndrome:
C) There is no facial paralysis.
The tongue is paralyzed on the ipsilateral side.
There is contralateral hemiplegia.
There are contralateral impaired sensations of position and movement.
The following statements concern the lateral medullary syndrome:
B) The nucleus ambiguus of the same side may be damaged.
There may be analgesia and thermoanesthesia on the ipsilateral side of the face.
Ipsilateral trunk and extremity hypalgesia and thermoanesthesia may occur.
Seizures usually do not occur.
The following statements concern the pons:
C) The basilar artery lies in a centrally placed groove on the anterior aspect of the pons.
The trigeminal nerve emerges on the anterior aspect of the pons.
Many nerve fibers present on the anterior aspect of the pons converge laterally to form the middle cerebellar peduncle.
The pons form the upper half of the floor of the fourth ventricle.
The following important structures are located in the brainstem at the level stated:
D) The trochlear nucleus lies within the midbrain at the level of the inferior colliculus.
The facial colliculus lies in the caudal part of the pons.
The motor nucleus of the trigeminal nerve lies within the cranial part of the pons.
The abducent nucleus lies within the caudal part of the pons.
The following statement concern the posterior surface of the pons:
A) The facial colliculus is produced by the root of the facial nerve winding around the nucleus of the abducent nerve.
Lateral to the median sulcus is an elongated swelling called the median eminence.
The floor of the superior part of the sulcus limitans is pigmented and is called the substantia ferruginea.
The vestibular area lies lateral to the sulcus limitans.
The following statements concern the transverse section through the caudal part of the pons:
A) The pontine nuclei lie between the transverse pontine fibers.
The trapezoid body is made up of fibers derived from the cochlear nuclei and the nuclei of the trapezoid body. The tegmentum is the part of the pons lying posterior to the trapezoid body.
The vestibular nuclei lie lateral to the abducent nucleus.
The medial longitudinal fasciculus lies below the floor of the fourth ventricle on each side of the midline.
The following statements concern a transverse section through the cranial part of the pons:
D) Bundles of corticospinal fibers lie among the transverse pontine fibers.
The motor nucleus of the trigeminal nerve lies medial to the main sensory nucleus in the tegmentum of the pons. The motor root of the trigeminal nerve is much smaller than the sensory root.
In the cranial part of the pons, the medial lemniscus has rotated so that its long axis lies transversely.
The medial longitudinal fasciculus is the main pathway that connects the vestibular and cochlear nuclei with the nuclei controlling the extraocular muscles (oculomotor, trochlear, and abducent nuclei).
The following statements concern the pons:
B) It lies in the posterior cranial fossa.
It is related anteriorly to the dorsum sellae of the sphenoid bone.
Astrocytoma of the pons is the most common tumor of the brainstem.
The pons receives its blood supply from the basilar artery.
The following statements concern the midbrain:
A) The superior brachium passes from the superior colliculus to the lateral geniculate body and the optic tract.
It passes superiorly through the opening in the tentorium cerebelli posterior to the dorsum sellae.
The oculomotor nerv emerges from the anterior surface of the midbrain at the level of the superior colliculi.
The interpeduncular fossa is bound laterally by the crus cerebri.
The following statements concern the internal structures of the midbrain:
B) The tectum is situated posterior to the cerebral aqueduct.
The crus cerebri lies anterior to the substantia nigra; whereas the tegmentum lies posterior to the substantia nigra.
The reticular formation present throughout the midbrain.
The central gray matter encircles the cerebral aqueduct.
The following statements concern the colliculi of the midbrain:
C) The superior colliculi are concerned with sight reflexes.
They are located in the tectum.
The inferior colliculi lie at the level of the trochlear nerve nuclei; whereas the superior colliculi lie at the level of the red nuclei.
The inferior colliculi are concerned with auditory reflexes.
The following statements concern the third cranial nerve nuclei:
B) The nerve fibers from the oculomotor nucleus pass through the red nucleus.
The oculomotor nucleus is situated in the central gray matter.
The parasympathetic part of the oculomotor nucleus is called the Edinger-Westphal nucleus.
The oculomotor nucleus lies close to the medial longitudinal fasciculus and lies anterior to the cerebral aqueduct.
A 63-year old man complaining of difficulty in swallowing, some hoarseness of his voice, and giddiness was seen by a neurologist. All these symptoms started suddenly 4 days previously. On physical examination, he was found to have a loss of the pharyngeal gagging reflex on the left side, left-sided facial analgesia, and left-sided paralysis of the vocal cord. Based on the clinical history and the results of the physical examination, select the most likely diagnosis.
B) Lateral medullary syndrome on the left side
A 7-year old girl was seen by a neurologist because she complained to her mother that she was seeing double. Careful physical examination revealed that the double vision become worse when she looked toward the left. The patient also had evidence of mild motor paralysis of her right lower limb without spasticity. There was also a slight facial paralysis involving the whole left side of the face. Based on the clinical history and the clinical examination, the following neurologic deficits could have been present except:
A) The mild right hemiparesis was caused by damage to the corticospinal tract on the right side.
The right-sided hemiparesis was caused by damage to the corticospinal tract on the left side of the pons. The corticospinal tract descends through the medulla and crosses to the right side of the midline at the decussation of the pyramids.
A 42-year old woman complaining of a severe, persistent headache visited her physician. At first, the headache was not continuous and tended to occur during the night. Now, the headache is present all the time and is felt over the whole head. Recently, she has begun to feel nauseous, and this has resulted in several episodes of vomiting. Last week, on looking in the mirror, she noted that her right pupil looked much larger than the left. Her right upper lid appeared to be drooped. The physical examination revealed the following most likely findings, except:
C) There was a loss of taste sensation on the posterior one-third of the tongue on the left side.
The sensation of taste on the posterior one-third of the tongue is supplied by the glosspharyngeal nerve, which originates in the medulla oblongata.
A 42-year old woman complaining of a severe, persistent headache visited her physician. At first, the headache was not continuous and tended to occur during the night. Now, the headache is present all the time and is felt over the whole head. Recently, she has begun to feel nauseous, and this has resulted in several episodes of vomiting. Last week, on looking in the mirror, she noted that her right pupil looked much larger than the left. Her right upper lid appeared to be drooped. The combination of the clinical history and the findings in the physical examination enabled the physician to make the following most likely diagnosis.
D) A tumor involving the right side of the brain at the level of the superior colliculi
The combination of raised intracranial pressure (headache, vomiting, and bilateral papilledema), the involvement of the right third cranial nerve (right-sided ptosis, right pupillary dilatation, and right-sided weakness of ocular deviation upward), spasticity of the left leg (right-sided corticospinal tracts), and ataxia of the right upper limb (cerebellar connections on the right side) led the physician to make a tentative diagnosis of an intracranial tumor in the right side of the midbrain at the level of the superior colliculi.
The cerebellum is the largest part of the hindbrain. It lies posterior to the fourth ventricle, the pons, and the medulla oblongata.
B) Both statements are true.
The cerebellum consists of two hemispheres joined by a narrow median called the
Vermis
True or False: The cerebellum is connected to the anterior aspect of the brainstem by three symmetrical bundles of nerve fibers called the superior, middle, and inferior cerebellar peduncles.
False
The cerebellum is connected to the posterior aspect of the brainstem.
True or False: The cerebellum is divided into three main lobes: the anterior lobe, the middle lobe, and the flocculonodular lobe.
True
The middle lobe is also known as the posterior lobe.
Which lobe of the cerebellum is the largest?
D) Posterior
Posterior lobe is also known as the middle lobe.
The cerebellum is composed on an outer covering of white matter called the cortex and inner gray matter. Embedded in the white matter of each hemisphere are three masses of gray matter forming the intracerebellar nuclei.
A) Only the second statement is true.
The cerebellum is composed on an outer covering of gray matter called the cortex and inner white matter.
The cerebellar cortex can be regarded as a large sheet with folds lying in the sagittal plane. Each fold or folium contains a core of gray matter covered superficially by white matter.
B) Both statements are false.
The cerebellar cortex can be regarded as a large sheet with folds lying in the coronal or transverse plane. Each fold or folium contains a core of white matter covered superficially by gray matter.
The gray matter of the cerebellar cortex throughout its extent has a uniform structure. Name its three layers from outer- to innermost.
MPG
The cerebellar cortex is divided into three layers:
1. Molecular layer - outermost
2. Purkinje cell layer - middle
3. Granular layer - innermost
True or False: The molecular layer of the cerebellar cortex contains two types of neurons: the outer basket cell and the inner stellate cell.
False
The molecular layer of the cerebellar cortex contains two types of neurons: the outer stellate cell and the inner basket cell.
Which of the following is incorrect about the functional areas of the cerebellum?
A) The intermediate zone controls the muscles in the distal parts of the limbs, especially the wrists and ankles.
The intermediate zone, which lies immediately lateral to the vermis, controls the muscles in the distal parts of the limbs, especially the hands and feet.
Four masses of gray matter are embedded in the white matter of the cerebellum on each side of the midline. From lateral to medial, these nuclei are the:
DEGF
Dentate
Emboliform
Globose
Fastigial
The dentate nucleus is the largest intracerebellar nuclei. It has the shape of a crumpled bag with the opening facing laterally.
A) Only the first statement is true.
It has the shape of a crumpled bag with the opening facing medially. The interior of the bag is filled with white matter made up of efferent fibers that leave the nucleus through the opening to form a large part of the superior cerebellar peduncle.
True or False: The fastigial nucleus lies near the midline in the vermis and close to the floor of the fourth ventricle.
False
The fastigial nucleus lies close to the roof of the fourth ventricle.
True or False: There is a large amount of white matter in each cerebellar hemisphere, but only a few in the vermis.
True
There is small amount of white matter in the vermis; it closely resembles the trunk and branches of a tree and thus is termed arbor vitae.
The white matter of the cerebellum is made of three groups of fibers: intrinsic, afferent, and efferent. All of the following statements below are true, except:
C) The afferent fibers enter the cerebellum mainly through the superior and inferior cerebellar peduncles.
The afferent fibers form the greater part of the white matter. They enter the cerebellum mainly through the middle and inferior cerebellar peduncles.
The great majority of the Purkinje cell axons pass to and synapse with the neurons of the cerebellar nuclei. However, a few Purkinje cell axons in the flocculonodular lobe and in part of vermis bypass the cerebellar nuclei and leave the cerebellum without synapsing.
Fibers from the dentate and emboliform nuclei leave the cerebellum through the superior cerebellar peduncle. Meanwhile, fibers from the globose and fastigial nuclei leave through the inferior cerebellar peduncle.
D) Only the first statement is true.
Fibers from the globose nuclei also leave the cerebellum through the superior cerebellar peduncle.
True or False: The climbing and mossy fibers constitute the two main line of input to the cortex are are inhibitory to the Purkinje cells.
False
The climbing and mossy fibers are excitatory to the Purkinje cells. Meanwhile, the stellate, basket, and Golgi cells serve as inhibitory interneurons by limiting the area of cortex excited and influencing the degree of Purkinje cell excitation produced by the climbing and mossy fiber input.
The climbing fibers are the terminal fibers of the pontocerebellar tracts. Meanwhile, the mossy fibers are the terminal fibers of all the other cerebellar afferent tracts.
B) Only the second statement is true.
The climbing fibers are the terminal fibers of the olivocerebellar tracts. Meanwhile, the mossy fibers are the terminal fibers of all the other cerebellar afferent tracts (e.g. corticopontocerebellar tract, anterior and posterior spinocerebellar tracts, cuneocerebellar tract, and vestibular nerve).
True or False: The mossy fibers have a much more diffused excitatory effect on Purkinje cells than the climbing fibers.
True
A single mossy fiber may stimulate thousands of Purkinje cells through the granule cells. Meanwhile, a single climbing fiber makes contact with only 1-10 Purkinje cells.
The cerebellum is linked to other parts of the central nervous system by numerous efferent fibers that are grouped together on each side into three large bundles, or peduncles. The superior cerebellar peduncles connect the cerebellum to the midbrain, the middle cerebellar peduncles connect the cerebellum to the pons, and the inferior cerebellar peduncles connect the cerebellum to the medulla oblongata.
D) Only the second statement is true.
The cerebellum is linked to other parts of the central nervous system by numerous afferent and efferent fibers.
The cerebral cortex sends information to the cerebellum by the following pathways, except:
C) None of these
The corticopontine fibers arise from nerve cells in the frontal, parietal, temporal, and occipital lobes of the cerebral cortex and descend through the corona radiata and internal capsule and terminate on the pontine nuclei. The pontine nuclei gives rise to transverse fibers of the pons, which cross the midline and enter the opposite cerebellar hemisphere as the superior cerebellar peduncle.
B) Only the first statement is true.
The pontine nuclei gives rise to transverse fibers of the pons, which cross the midline and enter the opposite cerebellar hemisphere as the middle cerebellar peduncle.
Which of the following is not true about the cerebro-olivocerebellar pathway?
D) The cortico-olivary fibers arise from nerve cells in the frontal, parietal, temporal, and occipital lobes of the cerebellar cortex.
The cortico-olivary fibers arise from nerve cells in the frontal, parietal, temporal, and occipital lobes of the cerebral cortex.
Which of the following is not true about the cerebroreticulocerebellar pathway?
D) None of these
All of the following are true about the anterior spinocerebellar tract, except:
B) Axons of the neurons in the nucleus dorsalis that do not cross over to the opposite side in the spinal cord cross within the cerebellum.
Axons of the neurons in the nucleus dorsalis that crossed over to the opposite side in the spinal cord cross back within the cerebellum.
The anterior spinocerebellar tract enters the cerebellum through the superior cerebellar pedunce; whereas the posterior spinocerebellar tract enters through the inferior cerebellar peduncle. Both these tracts terminate as mossy fibers in the cerebellar cortex.
D) Both statements are true.
The posterior spinocerebellar and cuneocerebellar tracts receive muscle joint information from the muscle spindles, tendon organs, and joint receptors. The posterior spinocerebellar tract receives such information from the trunk and lower limbs; whereas the cuneocerebellar tract receives them from upper limbs and upper thorax.
D) Both statements are true.
True or False: The globose and emboliform nuclei influence motor activity on the same side of the body.
True
The globose-emboliform-rubral pathway crosses twice, once in the decussation of the superior cerebellar peduncle and again in the rubrospinal tract close to its origin.
True or False: The dentate nucleus can influence motor activity by acting on the motor neurons of the ipsilateral cerebral cortex.
False
The dentate nucleus can influence motor activity by acting on the motor neurons of the contralateral cerebral cortex.
Axons of neurons in the dentate nucleus travel through the superior cerebellar peduncle and cross the midline to the opposite side in the decussation of the superior cerebellar peduncle. The fibers end by synapsing with cells in the contralateral ventrolateral nucleus of the thalamus. The axons of the thalamic neurons ascend through the internal capsule and corona radiata and terminate in the primary motor area of the cerebral cortex.
True or False: The dentate nucleus coordinate activity on the same side of the body.
True
Remember that the dentate nucleus can influence motor activity by acting on the contralateral cerebral cortex. The impulses from the motor cortex are transmitted to spinal segmental levels through the corticospinal tract. Most fibers of the corticospinal tract cross to the opposite side in the decussation of the pyramids or later at the spinal segmental levels. Thus, the dentate nucleus is able to coordinate muscle activity on the same side of the body.
The axons of the Purkinje cells project on different nuclei. Which of the following statements below regarding such projections is incorrect?
D) A few Purkinje cell axons pass directly out of the cerebellum and end on the medial vestibular nucleus in the brainstem.
A few Purkinje cell axons pass directly out of the cerebellum and end on the lateral vestibular nucleus in the brainstem.
True or False: A lesion in the cerebellar hemisphere gives rise to signs and symptoms that are limited to the same side of the body.
True
Each cerebellar hemisphere is connected by nervous pathways principally with the same side of the body.
In jerk nystagmus, movements are referred to as the slow phase away from the visual object, followed by a quick phase back toward the target. The slow phase is used to describe the form of nystagmus.
B) Only the first statement is true.
The quick phase is used to describe the form of nystagmus. For example, a patient is said to have a nystagmus to the left if the quick phase is to the left and the slow phase is to the right.
All of the following are manifestations of vermis syndrome, except:
D) Disturbances of voluntary movement
Involvement of the flocculonodular lobe results in signs and symptoms related to the vestibular system.
True or False: The most common cause of vermis syndrome is astrocytoma in children.
False
The most common cause of vermis syndrome is medulloblastoma of the vermis in children.
Nystagmus commonly occurs in diseases of the nervous system, eye, and inner ear. In cerebellar disease, the nystagmus is due to ataxia of muscles moving the eyeball.
B) Both statements are true.
There is a lack of coordination between the agonists and antagonists involved in the eyeball movement.
Acute lesions of the cerebellum, such as those resulting from a thrombosis of a cerebellar artery or a rapidly growing tumor, produce sudden and severe signs and symptoms. Patients will recover slowly from such injuries.
B) Only the first statement is true.
Acute cerebellar lesions produce sudden and severe signs and symptoms because of the sudden withdrawal of the influence on the cerebellum on muscular activity. Patients can recover quickly from such injuries because the cerebellum influences muscular activity indirectly through the vestibular nuclei, reticular formation, red nucleus, tectum, corpus striatum, and cerebral cortex. It may be that these other areas of the central nervous system take over this function.
The following statements concern the gross appearance of the cerebellum:
D) It is separated from the occipital lobes of the cerebral hemispheres by the tentorium cerebelli.
The anterior lobe is separated from the middle (posterior) lobe by the primary fissure.
The flocculonodular lobe is separated from the middle (posterior) lobe by the uvulonodular fissure.
The fourth ventricle lies anterior to the cerebellum.
The following general statements concern the cerebellum:
C) Each cerebellar hemisphere controls the tone of the skeletal muscle supplied by the spinal nerves on the same side of the body.
The cerebellum has the same influence on the skeletal muscles supplied by cranial nerves as on those supplied supplied by the spinal nerves. However, the cerebellum has no effect on smooth muscles.
The important Purkinje cells are Golgi type I neurons.
The Purkinje cells exert an inhibitory influence on the intracerebellar nuclei.
The following statements concern the structure of the cerebellum:
C) The gray matter of the cerebellum is found in the cortex and in the three masses forming the intracerebellar nuclei.
The inferior surface of the cerebellum shows a deep groove formed by the inferior surface of the vermis.
The inferior cerebellar peduncle joins the cerebellum to the medulla oblongata.
The white matter and folia of the cortex have a branched appearance on the cut surface, called the arbor vitae.
The following statements concern the structure of the cerebellar cortex:
B) The axons of the Purkinje cells form the efferent fibers from the cerebellar cortex.
The cortex is folded by many transverse fissures into folia.
The Purkinje cells are found in the middle layer, whereas the Golgi cells are found in the deepest layer of the cerebellar cortex.
The structure of the cortex is identical in different parts of the cerebellum.
The following statements concern the intracerebellar nuclei:
B) The axons of the nuclei form the main cerebellar outflow.
The nuclei are deeply embedded in the white matter.
The nuclei are located posterior to the roof of the fourth ventricle.
The nuclei are composed of large multipolar neurons.
The following statements concern the cerebellar peduncles:
B) In the superior cerebellar peduncle, most of the fibers are efferent and arise from the neurons of the intracerebellar nuclei.
The inferior cerebellar peduncle contains afferent fibers of the posterior spinocerebellar tract, the cuneocerebellar tract, the vestibular nucleus, and the olivocerebellar tract. In addition, there are efferent fibers from the cerebellum, including the fastigial vestibular pathway and the fastigial reticular pathway.
The middle cerebellar peduncle is formed of fibers that arise from the pontine nuclei.
The cerebellar peduncles are surface structures and are easily seen on dissection.
The following statements concern the afferent fibers entering the cerebellum:
B) The climbing and mossy fibers constitute the two main lines of input to the cerebellar cortex.
The mossy fibers end by making synaptic contacts with dendrites of the granular and Golgi cells.
The afferent fibers enter the cerebellum through the superior, middle, and inferior cerebellar peduncles.
The afferent fibers are myelinated and are excitatory to the Purkinje cells.
The following statements concern the functions of the cerebellum:
B) The cerebellum controls voluntary movement by coordinating the force and extent of contraction of different muscles.
The cerebellum influences the actions of muscles, not tendons.
The cerebellum inhibits the contraction of antagonistic muscles.
The cerebellum indirectly influences skeletal muscle activity with the assistance of the cerebral cortex.
The following statements concern the cerebellum:
D) The output of the cerebellar nuclei influences muscle activity so that movements can progress in an orderly sequence from one movement to the next.
The afferent mossy fibers may stimulate many Purkinje cells by first stimulating the granular cells.
The neurons of the intracerebellar nuclei sends axons to the ventrolateral nucleus of the thalamus, where they are relaxed to the cerebral cortex.
Past pointing is caused by the failure of the cerebellum to inhibit the cerebral cortex after the movement has begun.
The following statements concern the cerebellum:
D) The cerebellar cortex has the same uniform microscopic structure in different individuals.
The axons of the Purkinje cells exert a stimulatory influence on the neuron the deep cerebellar nuclei.
Each cerebellar hemisphere principally influences movement on the same side of the body.
The part of the cerebellum that lies in the midline is called the vermis.
Following thrombosis of the posterior inferior cerebellar artery, a patient presents the numbered signs and symptoms below. Match the signs and symptoms with the appropriate lettered structures involved. Each lettered option may be selected once, more than once, or not at all.
1. Loss of pain and temperature sensa a. Right reticulospinal tract
-tion on the left side of the body b. Right inferior cerebellar
2. Nystagmus peduncle
3. Hypotonicity of muscles on the right c. None of the above
with tendency to fall to the right
1. Loss of pain and temperature sensation on the left side of the body - none of the above
2. Nystagmus - right inferior cerebellar peduncle
3. Hypotonicity of muscles on the right with tendency to fall to the right - right inferior cerebellar peduncle
Match the numbered nerve tracts listed below with the lettered pathways by which they leave the cerebellum. Each lettered option may be selected once, more than once, or not at all.
1. Corticopontocerebellar a. Superior cerebellar peduncle
2. Cuneocerebellar b. Corpus callosum
3. Cerebellar reticular c. Striae medullaris
4. Cerebellar rubral d. Inferior cerebellar peduncle
e. Middle cerebellar peduncle
f. None of the above
4. Cerebellar rubral - superior cerebellar peduncle
A 45-yeard old man, who was an alcoholic, started to develop a lurching, staggering gait even when he was not intoxicated. The condition became slowly worse over a period of several weeks and then appeared to stabilize. Friends noticed that he had difficulty in walking in tandem with another person and tended to become unsteady on turning quickly. A thorough physical examination of this patient revealed the following findings, except:
C) While standing still, the patient stood with his feet together.
Patients with cerebellar disease frequently exhibit poor muscle tone, and to compensate for this, they stand stiff legged with their feet wide apart.
A 45-yeard old man, who was an alcoholic, started to develop a lurching, staggering gait even when he was not intoxicated. The condition became slowly worse over a period of several weeks and then appeared to stabilize. Friends noticed that he had difficulty in walking in tandem with another person and tended to become unsteady on turning quickly. The following additional abnormal signs might have been observed in this patient, except:
B) Paralysis of the right upper arm muscles
Although patients with cerebellar disease display disturbances of voluntary movement, none of the muscles are paralyzed or show atrophy.
Which of the following is not true about the cerebrum?
A) It is situated in the anterior fossa of the skull.
The cerebrum is situated in the anterior and middle cranial fossae of the skull.
The cerebrum may be divided into two parts: the diencephalon, which forms the central core, and the telencephalon, which forms the cerebral hemispheres.
The diencephalon can be divided into four major parts:
SHET
Subthalamus
Hypothalamus
Epithalamus
Thalamus
The thalamus is a large ovoid mass of white matter that forms the major part of the diencephalon. It serves as a cell station to all the main sensory systems, except the olfactory pathway.
C) Only the second statement is true.
The thalamus is a large ovoid mass of gray matter.
True or False: The thalamus is the center of integration of olfactory, visceral, and somatic afferent pathways.
False
The habenular nucleus is the center of integration of olfactory, visceral, and somatic afferent pathways.
True or False: The pineal gland possesses no nerve cells.
True
The pineal gland possesses no nerve cells, but adrenergic sympathetic fibers derived from the superior sympathetic ganglia enter enter the gland.
The pineal gland secretions, produced by the glial cells, reach their target organs via the bloodstream or through the cerebrospinal fluid. Their actions are mainly inhibitory and either directly inhibit the production of hormones or indirectly inhibit the secretion of releasing factors by the hypothalamus.
C) Only the second statement is true.
The pineal gland secretions are produced by pinealocytes, not glial cells.
When melatonin are released into the blood or cerebrospinal fluid, they pass through the anterior lobe of the pituitary gland where they stimulate the release of gonadotrophic hormone. Plasma melatonin level rises during the day and falls in darkness.
D) Both statements are false.
When melatonin are released into the blood or cerebrospinal fluid, they pass through the anterior lobe of the pituitary gland where they inhibit the release of gonadotrophic hormone. Plasma melatonin level rises in darkness and falls during the day.
True or False: Physiologically, there is hardly any activity in the body that is not influenced by the hypothalamus.
True
The hypothalamus controls and integrates the functions of the autonomic nervous system and the endocrine system. It also plays a vital role in maintaining body homeostasis.
True or false: The anterolateral corners of the optic chiasma are continuous with the optic tracts, and the posterolateral corners of the chiasma are continuous with the optic nerves.
False
The anterolateral corners of the optic chiasma are continuous with the optic nerves, and the posterolateral corners of the chiasma are continuous with the optic tracts.
True or False: Fibers originating from the temporal half of each retina cross the median plane at the optic chiasma to enter the optic tract of the opposite side.
False
Fibers originating from the nasal half of each retina cross the median plane at the optic chiasma to enter the optic tract of the opposite side.
All of the following structures form the neurohypophysis, except:
A) None of these
Pars nervosa is also known as the posterior lobe of the hypophysis.
Which of the following is not true about the third ventricle?
B) It has anterior, posterior, medial, lateral, superior, and inferior walls, and is line with ependyma.
The third ventricle has no medial wall.
The cerebral hemispheres are separated in midline by the longitudinal cerebral fissure. This fissure contains the sickle-shaped fold of dura mater, the falx cerebri, and the middle cerebral artery.
C) Only the first statement is true.
This fissure contains the sickle-shaped fold of dura mater, the falx cerebri, and the anterior cerebral artery.
True or False: Tentorium cerebelli is a horizontal fold of dura mater which separates the cerebral hemispheres from the cerebellum.
True
The frontal lobe occupies the area anterior to the central sulcus and superior to the lateral sulcus. The superolateral surface of the frontal lobe is divided by three sulci into four gyri.
C) Both statements are true.
The precentral sulcus runs parallel to the central sulcus, and the precentral gyrus lies between the,. Extending anteriorly from the precentral sulcus are the superior and inferior frontal sulci. The superior frontal gyrus lies superior to the superior frontal sulcus, the middle frontal gyrus lies between the superior and inferior frontal sulci, and the inferior frontal gyrus lies inferior to the inferior frontal sulcus.
The parietal lobe occupies the area posterior to the central sulcus and superior to the lateral sulcus. The lateral surface of the parietal lobe is divided by three sulci into four gyri.
A) Only the first statement is true.
The lateral surface of the parietal lobe is divided by two sulci into three gyri. The postcentral sulcus run parallel to the central sulcus, and the postcentral gyrus lies between them. Running posteriorly from the middle of the postcentral sulcus is the intraparietal sulcus. Superior to the intraparietal sulcus is the superior parietal gyrus, and inferiro to the intraparietal sulcus is the inferior parietal gyrus.
The temporal lobe occupies the area inferior to the lateral sulcus. The lateral surface of the temporal lobe is divided into three gyri by two sulci.
A) Both statements are true.
The superior and middle temporal sulci run parallel to the posterior ramus of the lateral sulcus and divide the temporal lobe into the superior, middle, and inferior temporal gyri.
Each lateral ventricle is roughly O-shaped cavity lined with ependyma and filled with cerebrospinal fluid. The lateral ventricle may be divided into body, which occupies the parietal lobe, and from which the anterior, posterior, and inferior horns extend into the frontal, occipital, and temporal lobes, respectively.
A) Only the second statement is true.
Each lateral ventricle is roughly C-shaped cavity.
The basal nuclei are masses of gray matter situated within each cerebral hemisphere and consist of the following, except:
A) None of these
True or False: The internal capsule separates the thalamus from the lentiform nucleus; whereas the external capsule separates the lentiform nucleus from the claustrum.
True
The white matter of the cerebral hemispheres is composed of myelinated nerve fibers of different diameters supported by neuroglia. The nerve fibers may be classified into three groups according to their connections. Name the three classifications.
CAP
Commisural fibers
Association fibers
Projection fibers
Commissural fibers connect corresponding regions of the two hemispheres. They are as follows: the corpus callosum, the anterior and superior commissures, the fornix, and the habenular commissure.
C) Only the first statement is true.
It should be anterior and posterior commissures.
Association fibers connect various cortical regions within the same hemisphere and may be divided into short and long groups. The short association fibers connect adjacent gyri and their fibers run parallel to the long axis of the sulci.
C) Only the first statement is true.
The fibers of short association fibers run transversely to the long axis of the sulci.
Which is the largest association fiber?
B) Superior longitudinal fasciculus
The superior longitudinal fasciculus connect the anterior part of the frontal lobe to the occipital and temporal lobes.
Since the thalamus is concerned with receiving sensory impulses from the same side of the body, the disability resulting from a lesion within it will be confined to the ipsilateral side of the body. There may be major impairment of all forms of sensation, which could include light touch, tactile localization, and discrimination, and loss of appreciation of joint movements.
D) Only the second statement is true.
Since the thalamus is concerned with receiving sensory impulses from the opposite side of the body, the disability resulting from a lesion within it will be confined to the contralateral side of the body.
The functions of the pineal gland are mainly inhibitory and have been shown to influence all of the following structures, except:
B) Thyroid gland
The pineal gland influences the pituitary gland, the islets of Langerhans, the parathyroids, the adrenals, and the gonads.
All of the following tumors may interfere with the function of the hypothalamus, except:
C) Astrocytoma
The most common abnormalities seen in lesions of hypothalamus include genital hypoplasia or atrophy, diabetes insipidus, obesity, disturbances of sleep, irregular pyrexia, and emaciation.
Each lateral ventricle contains about 7-10 mL of cerebrospinal fluid. This fluid is produced in the choroid plexus of the lateral ventricle and normally drains into the third ventricle through the cerebral aqueduct.
B) Only the first statement is true.
The cerebrospinal fluid drains into the third ventricle through the interventricular foramen (foramen of Monro).
The choroid plexus of the lateral ventricle is continuous with that of the fourth ventricle through the third ventricle. The choroid plexus is largest where the body and anterior and posterior horns join, and it is here where it may become with age.
D) Both statements are false.
The choroid plexus of the lateral ventricle is continuous with that of the third ventricle through the interventricular foramen (foramen of Monro). The choroid plexus is largest where the body and anterior and posterior horns join, and it is here where it may become with age.
True or False: Tumors of the caudate or lentiform nucleus pressing on the anterior two-thirds of the posterior limb of the internal capsule will cause progressive spastic hemiplegia, while more posteriorly situated tumors will cause sensory impairment on the opposite side.
True
True or False: If the corpus callosum fails to develop, no definite neurologic signs and symptoms will appear.
True
Should the corpus callosum be destroyed by disease later in life, each hemisphere becomes isolated, and the patient responds as if he or she has two separate brains.
The following statements concern the diencephalon:
D) It is bounded laterally by the internal capsule.
The diencephalon extends anteriorly as far as the interventricular foramen and posteriorly as far as the cerebral aqueduct.
The thalamus is situated on the lateral wall of the third ventricle.
The epithalamus consists of the habenular nuclei and their connections and the pineal gland.
The following statements concern the pineal gland:
D) Melatonin inhibits the release of gonadotrophic hormone from the anterior pituitary gland.
It produces a secretion that is translucent to x-rays.
There is an increase in the production of secretions of the pineal gland during darkness.
The pinealocytes are stimulated by the sympathetic nerve endings.
The following statements concern the thalamus:
D) It is separated from the lentiform nucleus by the internal capsule.
It forms the posterior boundary of the interventricular foramen.
It may be joined to the thalamus of the opposite side by the interthalamic connection.
It is a large ovoid mass of gray matter.
The following statements concern the hypothalamus:
A) Caudally, the hypothalamus merges with the tegmentum of the midbrain.
It is formed by the lower part of the lateral wall and floor of the third ventricle, below the hypothalamic sulcus.
The nuclei are composed of groups of small nerve cells.
Mammillary bodies are part of the hypothalamus.
The following statements concern the hypothalamus:
D) It gives off efferent fibers that pass to the sympathetic and parasympathetic outflow in the brain and spinal cord.
It receives many afferent visceral and somatic sensory nerve fibers.
It assists in the regulation of water metabolism.
It plays a role in controlling emotional states.
The following statements concern the third ventricle:
A) The posterior wall is formed by the opening into the cerebral aqueduct and the pineal recess.
The vascular tela choroidea projects from the roof of the third ventricle to form the choroid plexus.
Lying in the floor of the third ventricle, from anterior to posterior, are the optic chiasma, the tuber cinereum, and the mammillary bodies.
The wall of the third ventricle is lined with ependyma.
A 70-year old man with hypertension was admitted to an emergency department, having suddenly developed hemiparesis on the right side and numbness of the right leg. Axial CT and MRI were undertaken. MRI revealed a small hemorrhage in the left thalamus, which passed horizontally through the lateral ventricles. After careful observation, 2 days later the paresis was much improved, and the patient reported that his numbness had disappeared. The patient was discharged from the hospital 1 week later and made an uneventful recovery. His hypertension was brought under control with suitable medication. Using your knowledge of the relationships of the left thalamus, select the statement that explains the transient right hemiparesis and numbness.
B) The hemorrhage was small and occurred in the lateral part of the thalamus, producing transient edema in the left internal capsule.
A 70-year old man with hypertension was admitted to an emergency department, having suddenly developed hemiparesis on the right side and numbness of the right leg. Axial CT and MRI were undertaken. MRI revealed a small hemorrhage in the left thalamus, which passed horizontally through the lateral ventricles. After careful observation, 2 days later the paresis was much improved, and the patient reported that his numbness had disappeared. This hypertensive patient had a small thalamic hemorrhage. Select the most likely cause for the hemorrhage:
D) One of the diseased thalamic arteries may have ruptured.
An 8-year old boy with severe earache on the right side was taken to a pediatrician. The symptoms had started 7 days ago, and the pain had progressively worsened. On examination, the boy was found to have severe right-sided otitis media with acute mastoiditis. On being questioned, the boy admitted that his head hurt badly all over and that he felt sick. While he was being examined, he vomited. His body temperature was slightly elevated. In view of the severity of the headache and the presence of nausea and vomiting, the pediatrician decided to have an MRI performed. The result showed a small, well-defined, right cerebral abscess. The cerebral abscess in this patient was most likely located at which site?
D) Temporal lobe
True or False: The thickness of the cerebral cortex is uniform all throughout.
False
The thickness of the cortex varies from 1.5 to 4.5 mm. The cortex is thickest over the crest of a gyrus and thinnest in the depth of a sulcus.
The cerebral cortex, like gray matter elsewhere in the central nervous system, consists of a mixture of the nerve cells, nerve fibers, neuroglia, and blood vessels. The following are types of nerve cells present in the cerebral cortex, except:
B) Horizontal cells of Martinotti
The following types of nerve cells present in the cerebral cortex: pyramidal cells, stellate cells, fusiform cells, horizontal cells of Cajal, and cells of Martinotti.
Giant pyramidal cells whose cell bodies measure as much as 120 µm and are found in the motor precentral gyrus of the frontal lobe
C) Betz cells
The cerebral cortex is divided into layers that are distinguished by the type, density, and arrangement of their cells. Name the six layers from most superficial to deepest.
Mole Ex Ex In Gang Multi
Molecular (plexiform)
External granular
External pyramidal
Internal granular
Ganglionic (internal pyramidal)
Multiform (layer of polymorphic cells)
Layer of cerebral cortex where large number of synapses between different neurons occur
A) Molecular
Molecular (plexiform) layer is the most superficial layer.
Betz cells, which are large pyramidal cells that account for about 3% of the projection fibers of the corticospinal tract, are found in which layer of the cerebral cortex?
B) Internal pyramidal
The internal pyramidal layer is also known as the ganglionic layer.
True or False: All the areas of the cerebral cortex contain the six basic layers.
False
Those areas of the cortex in which the six basic layers cannot be recognized are referred to as heterotypical, as opposed to the majority, which are homotypical.
Which of the following is not true about the granular type of heterotypical area in the cerebral cortex?
D) It is found in the postcentral gyrus, inferior temporal gyrus, and in parts of the hippocampal gyrus.
It should be superior temporal gyrus.
Which of the following is not true about the agranular type of heterotypical area in the cerebral cortex?
A) Layers 3 and 5 are well-developed, having large and densely packed fusiform cells.
It should be pyramidal cells.
The anterior region of the precentral area is referred to as primary motor area. Meanwhile, the posterior region is referred to as secondary motor area.
B) Both statements are false.
The anterior region of the precentral area is referred to as secondary motor or premotor area. Meanwhile, the posterior region is referred to as primary motor area.
True or False: The primary and secondary motor areas contains giant pyramidal cells of Betz.
False
The secondary motor or premotor area has no giant pyramidal cells of Betz.
Electrical stimulation of the premotor area produces muscular movements similar to those obtained by stimulation of the primary motor area. However, weaker stimulation is necessary to produce the same degree of movement.
C) Only the first statement is true.
However, stronger stimulation is necessary to produce the same degree of movement.
True or False: Removal of the supplementary motor area produces no permanent loss of movement.
True
Stimulation of supplementary motor area results in movements of the contralateral limbs, but a stronger stimulus is necessary than when the primary motor area is stimulated.
True or False: Electrical stimulation of the frontal eye field causes conjugate movements of the eye, especially toward the same side.
False
It causes conjugate eye movements toward the opposite side.
The frontal eye field controls voluntary scanning movements of the eye and is independent of visual stimuli. The involuntary following of moving objects by the eyes involves the visual area of the occipital cortex to which the frontal eye field is connected by commissural fibers.
D) Only the first statement is true.
The frontal eye field is connected to the visual area by association fibers.
True or False: Ablation of Broca's area in the right cerebral hemisphere will result in paralysis of speech.
False
In the majority of individuals, Broca's area on the left or dominant hemisphere, and ablation will result in paralysis of speech. The ablation of this region in the nondominant hemisphere has no effect on speech.
Histologically, the anterior part of the postcentral gyrus (Brodmann area 3) is granular in type and contains only scattered pyramidal cells. The posterior part of the postcentral gyrus (Brodmann areas 1 and 2) possess fewer granular cells.
B) Both statements are true.
The primary somesthetic area (primary somatic sensory cortex) occupies the postcentral gyrus.
A quarter placed in the hand can be distinguished from a dime or a nickel by the size, shape, and feel of the coin without having to use one's eyes via Brodmann area:
B) 5 and 7
Brodmann areas 5 and 7 form the somesthetic association area.
True or False: The visual cortex receives fibers from the nasal half of the ipsilateral retina and the temporal half of the contralateral retina.
False
The visual cortex receives fibers from the temporal half of the ipsilateral retina and the nasal half of the contralateral retina.
True or False: The right half of the field of vision is represented in the visual cortex of the left cerebral hemisphere.
True
Likewise, the left half of the field of vision is represented in the visual cortex of the right cerebral hemisphere.
The macula densa, which is the central area of the retina and the area for most perfect vision, is represented on the cortex in the posterior part of area 17. It accounts for one-third of the visual cortex.
D) Only the second statement is true.
It should be macula lutea.
True or False: Electrical stimulation of the occipital eye field will produce conjugate eye movements toward the opposite side.
True
The function of the occipital eye field is believed to be reflex and associated with movements of the eye when it is following an object.
The primary auditory area consists of Brodmann areas 41 and 42. Area 41 is agranular type of cortex; whereas area 42 is homotypical and is mainly an auditory association area.
A) Only the first statement is true.
Area 41 is granular type of cortex.
True or False: The anterior part of the primary auditory area is concerned with reception of high-frequency sounds, while the posterior part is concerned with reception of low-frequency sounds.
False
The anterior part of the primary auditory area is concerned with reception of low-frequency sounds, while the posterior part is concerned with reception of low-frequency sounds.
True or False: A unilateral lesion of the primary auditory area produces partial deafness in both ears, the greater loss being in the contralateral ear.
True
Projection fibers to the auditory area arise principally in the medial geniculate body. Medial geniculate body receives fibers mainly from the organ of Corti of the opposite side as well as some fibers from the same side.
The Wernicke area is connected to the Broca area by a bundle of nerve fibers called the
B) Arcuate fasciculus
True or False: The Wernicke area receives fibers from the visual cortex in the occipital lobe and the auditory cortex in the superior temporal gyrus.
True
Thus, the Wernicke area permits the understanding of the written and spoken language and enables a person to read a sentence, understand it, and say it out loud.
All of the following functional areas are controlled by the dominant hemisphere, except:
C) Recognition of faces
Recognition of faces, spatial perception, and music are interpreted by the nondominant hemisphere.
True or False: The two cerebral hemispheres of the newborn have equipotential capabilities.
True
During childhood, one hemisphere slowly comes to dominate the other, and it is only after the first decade that the dominance becomes fixed.
True or False: Lesions of the primary motor cortex in one hemisphere result in paralysis of the contralateral extremities, with gross movement suffering the most.
False
Finer and more skilled movements suffer the most with lesions of the primary motor cortex.
The jacksonian epileptic seizure is due to an irritative lesion of the secondary motor area. The convulsion begins in the part of the body represented in the secondary motor area that is being irritated.
B) Both statements are false.
The jacksonian epileptic seizure is due to an irritative lesion of the primary motor area. The convulsion begins in the part of the body represented in the primary motor area that is being irritated.
True or False: Destruction of the primary motor area produces more severe paralysis than destruction of the secondary motor area.
True
Destruction of both areas produce the most complete form of contralateral paralysis.
Small discrete lesions of the primary motor cortex result in little change in muscle tone. Larger lesions involving the primary and secondary motor areas (areas 4 and 6) result in muscle spasticity.
A) Both statements are true.
The primary motor cortex gives origin to corticospinal and corticonuclear tracts, while the secondary motor cortex gives origin to the extrapyramidal tracts that pass to the basal ganglia and reticular formation. The corticospinal and corticonuclear tracts tend to increase muscle tone, but the extrapyramidal tracts decrease the muscle tone.
Destructive lesions of the frontal eye field of one hemisphere causes the two eyes to deviate away from the side of the lesion and an inability to turn the eyes to the same side. However, the involuntary tracking movement of the eyes when following moving objects is unaffected.
A) Only the second statement is true.
Destructive lesions of the frontal eye field of one hemisphere causes the two eyes to deviate to the side of the lesion and an inability to turn the eyes to the opposite side.
People who have lesion involving the _______ have difficulty pronouncing phonemes in their proper order and usually produce sounds that are close to the target word but are not exactly correct.
B) Insula
The following are true about the lesions of prefrontal cortex, except:
C) There is marked loss of intelligence.
Destruction of the prefrontal cortex does not produce any marked loss of intelligence.
Lesions of the primary somesthetic area of the cortex result in contralateral sensory disturbances, which are most severe in the distal parts of the limbs. Crude painful, tactile, and thermal stimuli often return.
A) Both statements are true.
Crude painful, tactile, and thermal stimuli often return, and is believed to be due to the function of the thalamus. The patient remains unable to judge degrees of warmth, unable to localize tactile stimuli accurately, and unable to judge weights of objects.
True or False: Lesions of the upper half of one primary visual area result in inferior quadrantic hemianopia, whereas lesion involving the lower half result in superior quadrantic hemianopia.
True
The upper half of the visual area is above the calcarine sulcus, whereas the lower half is below.
True or False: Lesions of the occipital pole produce peripheral scotomas.
False
Lesions of the occipital pole produce central scotomas.
True or False: Lesions of the secondary auditory area result to acoustic verbal agnosia.
True
Acoustic verbal agnosia, also known as word deafness, refers to inability to interpret sounds.
For normal consciousness, active functioning of which two main parts of the nervous system are necessary?
A) Reticular formation and cerebral cortex
The reticular formation is responsible for the state of wakefulness, while the cerebral cortex is responsible for the state of awareness.
In this condition, a person has an intact reticular formation but a nonfunctioning cerebral cortex.
B) Persistent vegetative state
The reticular formation is responsible for the state of wakefulness, while the cerebral cortex is responsible for the state of awareness. In persistent vegetative state, the person has sleep-wake cycles, but has no awareness and response to stimuli.
Which of the following is not true about sleep?
D) The eyes deviate downward.
During sleep:
1. The pulse rate, respiratory rate, and blood pressure fall.
2. The eyes deviate upward.
3. The pupils contract but react to light.
4. The tendon reflexes are lost.
5. The plantar reflex may become extensor.
True or False: Epilepsy is a symptom in which there is a sudden transitory disturbance of the normal physiology of the brain, usually the reticular formation.
False
Epilepsy is a symptom in which there is a sudden transitory disturbance of the normal physiology of the brain, usually the cerebral cortex.
The following statements concern the cerebral cortex:
C) From a functional point of view, the cerebral cortex is organized into vertical units of activity.
The largest giant pyramidal cells are found in the precentral gyrus.
In the visual cortex, the outer band of Baillarger is so thick that it can be seen with the naked eye.
The molecular layer is the most superficial layer of the cerebral cortex and is composed mainly of a dense network of tangentially oriented nerve fibers.
The following statements concern the precentral area of the frontal lobe of the cerebral cortex:
A) The posterior region is known as the primary motor area.
The function of the premotor area is to store programs of motor activity, which are conveyed to the primary motor area for the execution of movement.
The individual skeletal muscles are not represented in the primary motor area.
The area of the cerebral cortex controlling a particular movement is proportional to the skill of the movement.
The following statements concern the motor speech area of Broca:
B) In most individuals, this area is important on the left or dominant hemisphere.
The Broca's speech area brings about the formation of words by its connections with the primary motor area.
It is located in the inferior frontal gyrus between the anterior and ascending rami and the ascending and posterior rami of tBhe lateral fissure.
Brodmann areas 44 and 45 represent the motor speech area.
The following statements concern the primary somesthetic area:
A) The opposite half of the body is represented inverted.
Histologically, it contains large numbers of granular cells and few pyramidal cells.
Most sensations from different parts of the body reach the cortex from the contralateral side of the body; those from the hand also go only to the contralateral side.
The area extends onto the posterior part of the paracentral lobule.
The following statements concern the visual areas of the cortex:
A) The superior retinal quadrants pass to the inferior portion of the visual cortex.
The primary visual area is located in the walls of the posterior part of the calcarine sulcus.
The visual cortex receives afferent fibers from the lateral geniculate body.
The secondary visual area (Brodmann areas 18 and 19) surrounds the primary visual area on the medial and lateral surfaces of the hemisphere.
The following statements concern the superior temporal gyrus:
D) The primary auditory area is situated in the inferior wall of the lateral sulcus.
The main projection fibers to the primary auditory area arise from the medial geniculate body.
The sensory speech area of Wernicke is localized in the superior temporal gyrus in the dominant hemisphere.
The primary auditory area is sometimes referred to as Brodmann areas 41 and 42.
The following statements concern the association areas of the cerebral cortex:
B) The prefrontal area is concerned with the makeup of the individual's personality.
An appreciation of the body image is assembled in the posterior parietal cortex, and the right side of the body is represented in the left hemisphere.
They are concerned with interpretation of sensory experiences.
The association areas have all six cellular layers and are referred to as homotypical cortex. They form a large area of the cortical surface.
The following statements concern the cerebral dominance:
D) More than 90% of the adult population is right-handed and, therefore, is left hemisphere dominant.
The cortical gyri of the dominant and nondominant hemispheres are arranged in the same way.
About 96% of the adult population is left hemisphere dominant for speech.
After the first decade of life, the dominance of the cerebral hemispheres becomes fixed.
A 54-year old woman was seen by a neurologist because her sister had noticed a sudden change in her behavior. On questioning, the patient stated that after waking up from a deep sleep about a week ago, she noticed that the left side of her body did not feel as if it belonged to her. Later, the feeling worsened, and she became unaware of the existence of her left side. Her sister told the neurologist that the patient now neglects to wash the left side of her body. The neurologist examined the patient and found the following most likely signs, except:
B) There was definite evidence of muscular weakness of the upper and lower limbs on the left side.
The patient exhibited no weakness of her muscles on the left side despite the fact that her sister stated that she tended not to use her left leg.
A 54-year old woman was seen by a neurologist because her sister had noticed a sudden change in her behavior. On questioning, the patient stated that after waking up from a deep sleep about a week ago, she noticed that the left side of her body did not feel as if it belonged to her. Later, the feeling worsened, and she became unaware of the existence of her left side. Her sister told the neurologist that the patient now neglects to wash the left side of her body. The neurologist made the following likely conclusions, except:
C) The failure to look toward the left side (visual extinction) suggested a lesion existed in the left parieto-occipital lobes.
An MRI revealed a tumor in the right parieto-occipital lobes; a further lesion was present in the right frontal lobe.
True or False: Reticular formation contains highly organized groups of transmitter-specific cells that influence functions in specific areas of the central nervous system.
True
With newer techniques of neurochemistry and cytochemical localization, the reticular formation is shown to contain highly organized groups of transmitter-specific cells that influence functions in specific areas of the central nervous system.
All of the following are functions of the reticular formation, except:
D) None of these
Other functions of the reticular formation are control of the autonomic nervous system, influence on the biologic clocks, and arousal and level of consciousness.
These fibers decussate and join the hippocampi of the two sides
D) Commissure of fornix
The cortical structure of the parahippocampal gyrus is six layered. As the cortex is traced into the hippocampus, there is a gradual transition from a six- to a four-layered arrangement.
A) Only the first statement is true.
As the cortex is traced into the hippocampus, there is a gradual transition from a six- to a three-layered arrangement. These three layers are the molecular, the pyramidal, and the polymorphic layers.
Which of the following layers is not found in the dentate gyrus?
B) Pyramidal
Similar to parahippocampal gyrus, the dentate gyrus also has three layers, but the pyramidal layer is replaced by the granular layer.
Major output pathway of the limbic system
D) Hypothalamus
Unilateral or bilateral destruction of the amygdaloid nucleus and the para-amygdaloid area results to a syndrome called
B) Kluver-Bucy
Kluver-Bucy syndrome is characterized by the following signs and symptoms:
1. Decreased aggressiveness
2. Emotional instability
3. Restlessness
4. Increased interest in food
5. Hypersexuality
6. No disturbance in memory
True or False: Humans in whom the amygdaloid area is destroyed usually demonstrate Kluver-Bucy syndrome.
False
Humans in whom the amygdaloid area is destroyed do not usually demonstrate Kluver-Bucy syndrome. It was, however, described in humans following the bilateral removal of large areas of the temporal lobes.
The olfactory aura that preceded the general convulsions of the epileptic attack would indicate that the _____ lobe of the cerebral cortex was initially involved.
D) Temporal
The following statements concern the reticular formation:
C) Superiorly, the reticular formation is relayed to the cerebral cortex.
The reticulobulbar and reticulospinal tracts form the efferent pathways from the reticular formation to the motor nuclei of the cranial nerves and the anterior horn cells of the spinal cord, respectively.
The reticular formation extends through the neuroaxis from the spinal cord to the thalamus.
The main pathways through the reticular formation are poorly defined and are difficult to trace from one part of the central nervous system to another using silver stains.
The following statements concern the functions of the reticular formation:
A) It influences the activity of alpha and gamma motor neurons.
It does not oppose the actions of the vestibular spinal tracts. In fact, it helps maintain the tone of the antigravity muscles.
It brings about reciprocal inhibition during contraction of the prime mover muscles.
It can modulate reflex activity.
The following statements concern the functions of the reticular formation:
B) By means of its reticulobulbar and reticulospinal tracts, it can control the parasympathetic and sympathetic outflows.
It can influence all ascending pathways to the supraspinal levels.
It can affect the biologic rhythm.
It does affect the reception of pain.
Anatomically, the following structures collectively form the limbic system:
D) The subcallosal, the cingulate, and the parahippocampal gyri, the hippocampal formation, the amygdaloid nucleus, the mammillary bodies, and the anterior thalamic nuclei
The following statements concern the efferent connections of the hippocampus:
C) They travel through the fornix.
They arise from large pyramidal cells of the cortex.
The fibers within the fornix pass anterior to the interventricular foramen.
Some of the fibers end in the anterior nuclei of the thalamus.
The following statements concern the functions of the limbic system:
C) The hippocampus is concerned with recent memory.
It is not concerned with visual experiences.
It plays no role in olfactory function.
It indirectly influences the activity of the endocrine system.
True or False: The subthalamic nuclei, the substantia nigra, and the red nucleus are included in the basal nuclei.
False
The basal nuclei consist of the corpus striatum, the amygdaloid nucleus, and the claustrum. Although the subthalamic nuclei, the substantia nigra, and the red nucleus are functionally closely related to the basal nuclei, they should not be included with them.
The corpus striatum is situated medial to the thalamus. It is almost completely divided by the internal capsule into globus pallidus and putamen.
C) Both statements are false.
The corpus striatum is situated lateral to the thalamus. It is almost completely divided by the internal capsule into caudate nucleus and lentiform nucleus.
The lentiform nucleus consists of:
C) Globus pallidus and putamen
The striatum consists of:
D) Caudate nucleus and putamen
The corpus striatum consists of:
B) Caudate nucleus and lentiform nucleus
Which of the following is not true about the caudate nucleus?
B) It is closely related to the third ventricle.
It is closely related to the lateral ventricle.
Which of the following is not true about the lentiform nucleus?
A) It is separated from the subcortical white matter of the insula by the external capsule.
The lentiform nucleus is separated from the claustrum by the external capsule. The claustrum, in turn, separates the external capsule from subcortical white matter of the insula.
True or False: The darkness of the globus pallidus is due to the presence of a high concentration of unmyelinated nerve fibers.
False
The paleness of the globus pallidus is due to the presence of a high concentration of myelinated nerve fibers. Hence, globus pallidus is also known as paleostriatum.
True or False: A vertical plate of white matter divides the lentiform nucleus into a larger darker lateral portion, the globus pallidus, and an inner lighter portion, the putamen.
False
A vertical plate of white matter divides the lentiform nucleus into a larger darker lateral portion, the putamen, and an inner lighter portion, the globus pallidus.
The caudate nucleus and globus pallidus form the main sites of receiving input to the basal nuclei. The putamen forms the major site from which the output leaves the basal nuclei.
D) Both statements are false.
The caudate nucleus and putamen form the main sites of receiving input to the basal nuclei. The globus pallidus forms the major site from which the output leaves the basal nuclei.
Various parts of the brain form connection with the corpus striatum and vice versa. Which of the following pairs below is incorrectly matched?
A) Brainstem striatal fibers - norepinephrine
It should be serotonin.
All of the following neurotransmitters are liberated at the terminals of striatonigral fibers, except:
B) Serotonin
Striatonigral fibers pass from the caudate nucleus and putamen to the substantia nigra. Some of the fibers use GABA or acetylcholine as the neurotransmitter, while the others used substance P.
True or False: Ansa lenticularis are pallidofugal fibers which pass to the thalamus, while fasciculus lenticularis are pallidofugal fibers which pass to the subthalamus.
True
Other examples of pallidofugal fibers are pallidotegmental fibers which terminate in the caudal tegmentum of the midbrain, and the pallidosubthalamic fibers which pass to the subthalamic nuclei.
The activity of the basal nuclei is initiated by information received from all of the following structures, except:
B) Primary motor cortex
The activity of the basal nuclei is initiated by information received from the premotor and supplemental areas of the motor cortex, the primary sensory cortex, the thalamus, and the brainstem.
True or false: The basal nuclei control muscular movements by influencing the brainstem and spinal cord.
True
The basal nuclei control muscular movements by influencing the cerebral cortex and have no direct control through descending pathways to the brainstem and spinal cord.
True or False: Parkinson disease is a combination of hyperkinetic and hypokinetic motor disturbances.
True
In hyperkinetic disorders, there are excessive and abnormal movements, such as seen with chorea, athetosis, and ballism. In hypokinetic disorders, there is a lack or slowness of movement.
Which of the following is not true about Huntington disease?
D) It is an autosomal recessive inherited disease, with onset occurring most often in adult life.
Huntington disease is an autosomal dominant inherited disease.
In Huntington's disease, there is a degeneration of the GABA-secreting, substance P-secreting, and acetylcholine-secreting neurons of the striatonigral-inhibiting pathway. This results in the dopamine-secreting neurons of the substantia nigra to become overactive; thus, the nigrostriatal pathway inhibits the caudate nucleus and putamen.
D) Both statements are true.
The inhibition of the caudate nucleus and putamen by the nigrostriatal pathway produces the choreiform movements in this disease.
Which of the following is not true about Syndenham chorea (St. Vitus' dance)?
B) The host's antibodies not only combine with the staphylococcal bacterial but also attack the membranes of the neurons of the basal ganglia.
The antigens of the streptococcal bacteria are similar in structure to the proteins present in the membranes of the striatal neurons. The host's antibodies not only combine with the bacterial antigens but also attack the membranes of the neurons of the basal ganglia.
True or False: The Parkinson disease is associated with neuronal degeneration in the substantia nigra and, to a lesser extent, in the globus pallidus, putamen, and caudate nucleus.
True
Globus pallidus, putamen, and caudate nucleus are collectively known as the corpus striatum.
The following statements concern the basal nuclei (ganglia):
B) The head of the caudate nucleus is connected to the putamen.
The caudate nucleus and the putamen form the neostriatum (striatum).
The internal capsule lies medial to the apex of the globus pallidus.
The basal nuclei are formed of gray matter.
The following statements concern the basal nuclei (ganglia):
C) The amygdaloid nucleus is connected to the caudate nucleus.
The lentiform nucleus is not divided by the external capsule into the globus pallidus and the putamen.
The claustrum forms a part of the basal nuclei. However, its function is unknown.
The corpus striatum lies lateral to the thalamus.
The following statements concern the basal nuclei (ganglia):
A) The tail of the caudate nucleus lies in the roof of the lateral ventricle.
The head of the caudate nucleus lies medial to the internal capsule.
The insula does not form part of the basal nuclei.
The subthalamic nuclei are functionally closely related to the basal nuclei but are not considered part of them.
The following statements concern the caudate nucleus:
C) The tail terminates anteriorly in the amygdaloid nucleus.
It is a C-shaped mass of gray matter.
The body of the caudate nucleus forms part of the floor of the body of the lateral ventricle.
The head of the caudate nucleus lies lateral to the anterior horn of the lateral ventricle.
The following statements concern the afferent corticostriate fibers to the corpus striatum:
D) All parts of the cerebral cortex send fibers to the caudate nucleus and putamen.
Each part of the cerebral cortex is projected to specific parts of the corpus striatum.
The largest input to the different parts of the corpus striatum is from the sensory-motor part of the cerebral cortex.
Most of the projection fibers are from the cerebral cortex of the same side.
The following statements concern the nigrostriate fibers:
A) The neurons in the substantia nigra send axons to the putamen.
Dopamine is the neurotransmitter.
The nigrostriate fibers are inhibitory in function.
Parkinson disease is caused by a reduction in the release of dopamine within the corpus striatum.
The following statements concern the efferent fibers of the corpus striatum:
A) Some of the striatopallidal fibers have GABA as the neurotransmitter.
None of the efferent fibers from the corpus striatum descend directly to the motor nuclei of the cranial nerves.
None of the efferent fibers from the corpus striatum pass directly to the cerebellum.
The anterior horn cells of the spinal cord are not influenced directly by the efferent fibers from the corpus striatum.
The following statements concern the functions of the basal nuclei (ganglia):
C) The activities of the globus pallidus precede the activities of the motor cortex concerned with discrete movements of the hands and feet.
The outflow of the basal nuclei is channeled through the globus pallidus to the motor areas of the cerebral cortex, thus influencing muscular activities.
The globus pallidus influences movements of the entire body.
The activities of the basal nuclei are initiated by information received from the sensory cortex, the thalamus, and the brainstem.
True or False: Bilateral connections are present for all the cranial nerve nuclei.
False
Bilateral connections are present for all the cranial nerve nuclei except for part of the facial nucleus that supplies the muscles of the lower part of the face and a part of the hypoglossal nucleus that supplies the genioglossus muscle.
The general visceral motor nuclei form the cranial outflow of the parasympathetic portion of the autonomic nervous system. Name the five nuclei.
SLIDE
Superior salivatory nucleus of facial nerve
Lacrimal nucleus of facial nerve
Inferior salivatory nucleus of facial nerve
Dorsal motor nucleus of vagus nerve
Edinger-Westphal nucleus of oculomotor nerve
The special somatic afferent component of cranial nerves concerns hearing, balance, and vision. Meanwhile, the special visceral afferent component concerns taste and smell.
C) Both statements are true.
Somatic striated muscles are innervated by cranial nerves with general visceral efferent component. Meanwhile, branchial arch striated muscles are innervated by cranial nerves with special visceral efferent.
A) Only the second statement is true.
Somatic striated muscles are innervated by cranial nerves with general somatic efferent component.
All of the following cranial nerves have special visceral afferent component, except:
A) Optic
The special visceral afferent component concerns taste and smell.
1. Olfactory - smell
2. Facial - taste from anterior two-thirds of tongue
3. Glossopharyngeal - taste from posterior one-third of tongue
All of the following cranial nerves have special somatic afferent component, except:
D) Olfactory
The special somatic afferent component concerns hearing, vision, and balance.
1. Optic - vision
2. Vestibular portion of vestibulocochlear - balance
3. Cochlear portion of vestibulocochlear - hearing
All of the following cranial nerves have general somatic afferent, except:
A) Facial
The general somatic afferent component concerns general sensations.
1. Trigeminal
a. Opthalmic - cornea; skin of forehead, scalp, eyelids, and nose; mucus membrane of paranasal sinuses and nasal cavity
b. Maxillary - skin of face over maxilla; teeth of upper jaw; mucus membrane of nose, maxillary sinus, and palate
c. Mandibular (sensory) - skin of cheek; skin over mandible and side of head; teeth of lower jaw; TMJ; mucus membrane of mouth; anterior two-thirds of tongue
2. Glossopharyngeal (sensory) - posterior one-third of tongue and pharynx
3. Vagus (sensory) - larynx, trachea, bronchi
True or False: Only glossopharyngeal and vagus nerves have general visceral afferent component.
True
The general visceral afferent component concerns visceral sensations.
1. Glossopharyngeal - carotid body (chemoreceptor) and carotid sinus (baroreceptor)
2. Vagus - lungs; alimentary tract from pharynx to splenic flexure of colon; liver, kidneys, and pancreas
All of the following cranial nerves have general somatic efferent component, except:
D) Facial
The general somatic efferent component concerns somatic striated muscles.
4. Hypoglossal - muscles of tongue (except palatoglossus)
All of the following cranial nerves have general visceral efferent component, except:
A) Trigeminal
The general visceral efferent component concerns glands and smooth muscles (parasympathetic innervation).
1. Oculomotor - constrictor pupillae
2. Facial - submandibular and sublingual salivary glands; lacrimal glands; glands of nose and palate
3. Glossopharyngeal - parotid salivary gland
4. Vagus - heart and great thoracic blood vessels, bronchi, alimentary tract
All of the following cranial nerves have special visceral efferent component, except:
D) Trigeminal
The special visceral efferent component concerns branchial arch striated muscles.
1. Facial - muscles of face and scalp; stapedius muscle; posterior belly of digastric and stylohyoid muscles
2. Cranial root of accessory - muscles of soft palate (except tensor veli palatini); muscles of pharynx (except stylopharyngeus); and muscles of larynx (except cricothyroid)
3. Spinal root of accessory - sternocleidomastoid and trapezius muscles
The following are possible exit points of the facial nerve in the skull, except:
C) External acoustic meatus
The lateral stria of the olfactory tract carries axons to the olfactory area of the cerebral cortex, nanely, the periamygdaloid and prepiriform areas. Meanwhile, the medial stria of the olfactory tract carries axons that cross the median plane in the posterior commissure to pass to the olfactory bulb of the opposite side.
D) Only the first statement is true.
The medial stria of the olfactory tract carries axons that cross the median plane in the anterior commissure.
The periamygdaloid and prepiriform areas of the parahippocampal gyrus are often known as the primary olfactory cortex. The entorhinal area of the cerebral cortex is known as the secondary olfactory cortex.
C) Both statements are false.
The periamygdaloid and prepiriform areas are found in the cerebral cortex, whereas the entorhinal area is found in the parahippocampal gyrus.
True or False: The olfactory afferent pathway has only two neurons and reaches the cerebral cortex without synapsing in one of the thalamic nuclei.
True
In contrast to all other sensory pathways, the olfactory afferent pathway has only two neurons and reaches the cerebral cortex without synapsing in one of the thalamic nuclei.
True or False: The olfactory nerve fibers are myelinated and are covered with Schwann cells.
False
The olfactory nerve fibers are unmyelinated and are covered with Schwann cells.
True or False: The optic nerve fibers are myelinated, and their sheaths are formed from Schwann cells.
False
The optic nerve fibers are myelinated, and their sheaths are formed from oligodendrocytes rather than Schwann cells, since the optic nerve is comparable to a tract within the central nervous system.
True or False: In the optic chiasma, the fibers from the nasal (medial) half of each retina, including the nasal half of the macula, cross the midline and enter the optic tract of the opposite side.
True
Meanwhile, the fibers from the temporal (lateral) half of each retina, including the temporal half of the macula, pass posteriorly in the optic tract of the same side.
True or False: Most of the fibers from the optic tract terminate by synapsing with nerve cells in the superior colliculus of the midbrain.
False
Most of the fibers from the optic tract terminate by synapsing with nerve cells in the lateral geniculate body of the thalamus. A few fibers pass to the pretectal nucleus and superior colliculus of the midbrain and are concerned with light reflexes.
True or False: Three neurons conduct visual impulses to the visual cortex.
False
Four neurons conduct visual impulses to the visual cortex:
1. Rods and cones, which are specialized receptor neurons in the retina
2. Bipolar neurons, which connect rods and cons to the ganglion cells
3. Ganglion cells, whose axons pass to the lateral geniculate body
4. Neurons of the lateral geniculate body, whose axons pass to the cerebral cortex
True or False: The image of an object projected in the right field of vision is projected on the nasal half of the right retina and the temporal half of the left retina.
True
True or False; In the optic chiasma, the axons from the nasal half of the right retina and the axons from the temporal half of the left retina combine to form the left optic tract.
True
Likewise, the axons from the nasal half of the left retina and the axons from the temporal half of the right retina combine to form the right optic tract.
True or False: The lower retinal quadrants (upper field of vision) project on the lower wall of the calcarine sulcus, while the upper retinal quadrants (lower field of vision) project on the upper wall of the sulcus.
True
True or False: Macula lutea is represented on the anterior part of area 17.
False
Macula lutea is represented on the posterior part of area 17, and the periphery of retina is represented anteriorly.
True or False: If light is shone into one eye, the pupils of both eyes normally constrict.
True
The constriction of the pupil on which the light is shone is called the direct light reflex. The constriction of the opposite pupil, even though no light fell on that eye, is called the consensual light reflex.
True or False: The pretectal nucleus of the optic nerve sends fibers to the Edinger-Westphal nuclei on both sides of the midbrain.
True
Both pupils constrict in light reflex because the pretectal nucleus sends fibers to the parasympathetic nuclei on both sides of the midbrain.
When the eyes are directed from a distant to a near object, all of the following occurs, except:
B) The lens thicken to increase its refractive power by contraction of the radial muscle.
The lens thicken to increase its refractive power by contraction of the ciliary muscle. The radial muscle is found in the iris.
All of the following is true about the corneal reflex, except:
A) The facial nerve and its branches supply the orbicularis oris muscle, which causes closure of the eyelids.
The facial nerve and its branches supply the orbicularis oculi muscle, which causes closure of the eyelids.
True or False: In pupillary skin reflex, the pupil will constrict if the skin is painfully stimulated by pinching.
False
In pupillary skin reflex, the pupil will dilate if the skin is painfully stimulated by pinching.
The main oculomotor nucleus is situated in the anterior part of the gray matter that surrounds the cerebral aqueduct. It consists of groups of nerve cells that supply all the extrinsic muscles of the eye except the inferior oblique and the lateral rectus.
B) Only the first statement is true.
It consists of groups of nerve cells that supply all the extrinsic muscles of the eye except the superior oblique and the lateral rectus.
True or False: The accessory parasympathetic nucleus of the oculomotor nerve receives corticonuclear fibers for the accommodation reflex and fibers from the pretectal nucleus for the direct and consensual light reflexes.
True
The accessory parasympathetic nucleus is also known as the Edinger-Westphal nucleus.
The oculomotor nerve is entirely motor and is responsible for all of the following, except:
D) Dilating the pupil
It should be constricting the pupil.
True or False: The main oculomotor nucleus lies at the level of the superior colliculus, while the trochlear nucleus lies at the level of the inferior colliculus of the midbrain.
True
The trochlear nucleus lies inferior to the main oculomotor nucleus.
The trochlear nucleus receives all of the following fibers, except:
D) None of these
The trochlear nucleus receives:
1. Corticonuclear fibers from both cerebral hemispheres
2. Tectobulbar fibers, which connect the trochlear nucleus to the visual cortex through the superior colliculus
3. Medial longitudinal fasciculus, which is connected to the nuclei of the third, sixth, and eighth cranial nerves
Which of the following is incorrect about the trochlear nerve?
C) It is entirely motor and assist in turning the eye downward and medially.
The trochlear nerve innervates the superior oblique muscle, which turns the eye downward and laterally.
True or False: The trigeminal nerve is the largest cranial nerve and has four nuclei.
True
The trigeminal nerve has four nuclei:
1. Main sensory nucleus - lies in the posterior part of the pons, lateral to the motor nucleus; continuous below with the spinal nucleus
2. Spinal nucleus - continuous superiorly with the main sensory nucleus in the pons and extends inferiorly through the whole length of the medulla oblongata and into the upper part of the spinal cord as far as the second cervical segment
3. Mesencephalic nucleus - extends inferiorly in the pons as far as the main sensory nucleus
4. Motor nucleus - situated in the pons medial to the main sensory nucleus
Which of the following is not true about the spinal nucleus of the trigeminal nerve?
A) The sensations of touch and pressure pass to the spinal nucleus
The sensations of pain and temperature pass to the spinal nucleus. The sensations of touch and pressure pass to the main sensory nucleus.
The different nuclei of the trigeminal nerve each convey different sensations. Which of the following pairs below is incorrectly matched?
D) None of these
The axons of the sensory nuclei of the trigeminal nerves cross the median plane and ascend as the spinal lemniscus to terminate on the nerve cells of the ventral posteromedial nucleus of the thalamus. The axons of these cells then travel through the internal capsule to the precentral gyrus.
B) Both statements are false.
The axons of the sensory nuclei of the trigeminal nerve cross the median plane and ascend as the trigeminal lemniscus. Spinal lemniscus is formed by the anterior spinothalamic, lateral spinothalamic, and spinotectal tracts.
The axons of the nerve cells of the ventral posteromedial nucleus of the thalamus travel through the internal capsule to the postcentral gyrus.
All of the following are muscle supplied by the motor nucleus of the trigeminal nerve, except:
A) Levator veli palatini
It should be tensor veli palatini. The motor nucleus of the trigeminal nerve also innervates the muscles of mastication, namely, the masseter, the temporalis, and the medial and lateral pterygoids.
True or False: The maxillary and mandibular divisions of the trigeminal nerve contains both motor and sensory fibers.
False
The opthalmic division contains only sensory fibers and leaves the skull through the superior orbital fissure to enter the orbital cavity. The maxillary division also contains only sensory fibers and leaves the skull through the foramen rotundum. The mandibular division contains both sensory and motor fibers and leaves the skull through the foramen ovale.
True or False: The sensory fibers of the trigeminal nerve to the skin of the face from each division supply a distinct zone, there being little or not overlap of the dermatomes.
True
The sensory fibers of the trigeminal nerve to the skin of the face from each division supply a distinct zone, there being little or not overlap of the dermatomes (compared with the overlap of the dermatomes of the spinal nerves).
True or False: The skin over the angle of the jaw is supplied by the mandibular division of the trigeminal nerve.
False
The skin over the angle of the jaw is supplied by the greater auricular nerve (C2 and C3) and not by branches of the trigeminal nerve.
True or False: The facial nerve has two nuclei.
False
The facial nerve has three nuclei: the main motor nucleus, the parasympathetic nucleus, and the sensory nucleus.
True or False: The muscles on the upper part of the face receive corticonuclear fibers from both cerebral hemispheres, whereas the muscles on the lower part of the face only receive only corticonuclear fibers from the opposite cerebral hemisphere.
True
These pathways explain the voluntary control of facial muscles. However, another involuntary pathway exists; it forms a part of the reticular formation and controls the mimetic or emotional changes in facial expression.
All of the following muscles are supplied by the motor nucleus of the facial nerve, except:
A) Mylohyoid
It should be stylohyoid. The motor nucleus of the facial nerve also supplies the muscles of facial expression.
The following structures are supplied by the superior salivatory nucleus of the facial nerve, except:
A) Lacrimal gland
The lacrimal gland is supplied by the lacrimal nucleus. The superior salivatory nucleus also supplies the sublingual salivary gland.
The sensory nucleus of the facial nerve receives taste fibers from the:
D) All of these
Which of the following is incorrect about the vestibular nerve?
A) Few of its fibers pass directly to the cerebellum through the middle cerebellar peduncle, bypassing the vestibular nuclei.
Few of its fibers pass directly to the cerebellum through the inferior cerebellar peduncle, bypassing the vestibular nuclei.
Which of the following is not true about the cochlear nerve?
D) It enters the anterior surface of the brainstem at the lower border of the pons on the medial side of the emerging facial nerve.
It enters the anterior surface of the brainstem at the lower border of the pons on the lateral side of the emerging facial nerve and is separated from it by the vestibular nerve.
True or False: Afferent impulses from the carotid sinus, a baroreceptor situated at the bifurcation of the common carotid artery, travel with the glossopharynegeal nerve.
True
They terminate in the nucleus of the tractus solitarius and are connected to the dorsal motor nucleus of the vagus nerve. The carotid sinus reflex that involves the glossopharyngeal and vagus nerves assists in the regulation of arterial blood pressure.
Which of the following is not true about the course of the glossopharyngeal nerve?
C) It descends through the upper part of the neck in company with the external jugular vein and the internal carotid artery to reach the posterior border of the stylopharyngeus muscle, which it supplies.
It descends through the upper part of the neck in company with the internal jugular vein and the internal carotid artery.
True or False: Both glossopharyngeal and vagus nerves lie deep in the reticular formation of the medulla oblongata and are formed by the nucleus tractus solitarius.
False
Both glossopharyngeal and vagus nerves are formed by the nucleus ambiguus.
Which of the following is incorrect about the vagus nerve?
A) The left vagus nerve is distributed to the stomach, liver, upper part of the duodenum, and the tail of the pancreas.
The left vagus nerve is distributed to the stomach, liver, upper part of the duodenum, and the head of the pancreas.
The right vagus nerve is now called the posterior vagal trunk, whereas the left vagus nerve is now called the anterior vagal trunk.
The cranial and spinal roots of the accessory nerve unite and leave the skull through the jugular foramen. The roots then separate, and the cranial root joins the vagus nerve.
D) Both statements are true.
The cranial root joins the vagus nerve and is distributed in its pharyngeal and recurrent laryngeal branches to the muscles of the soft palate, pharynx, and larynx.
True or False: The hypoglossal nucleus receives corticonuclear fibers from both cerebral hemispheres.
False
However, the cells responsible for supplying the genioglossus muscle only receive corticonuclear fibers from the opposite cerebral hemisphere.
True or False: The hypoglossal nerve fibers pass anteriorly through the medulla oblongata and emerge as a series of roots in the groove between the olive and the inferior cerebellar peduncle.
False
The hypoglossal nerve fibers emerge as a series of root in the groove between the pyramid and the olive.
True or False: The cranial nerves that possess efferent sensory fibers have cell bodies that are found in the ganglia along the course of the nerve; these are equivalent to the posterior root ganglia.
False
The cranial nerves that possess afferent sensory fibers have cell bodies that are found in the ganglia along the course of the nerve.
Bilateral anosmia can be caused by disease of the olfactory mucus membrane, such as the common cold or allergic rhinitis. Unilateral anosmia can be caused by disease of the olfactory nerves, bulb, or tract.
C) Both statements are true.
True or False: A lesion of olfactory cortex on one side is unlikely to produce complete anosmia.
True
A lesion of olfactory cortex on one side is unlikely to produce complete anosmia, because the fibers from each olfactory tract travel to both cerebral hemispheres.
Which of the following is incorrect about lesions of the visual pathway?
A) Bitemporal hemianopia result from a sagittal section of the optic chiasma, most commonly produced by a tumor of the pineal gland exerting pressure on the optic chiasma.
Sagittal section of the optic chiasma is most commonly produced by a tumor of the pituitary gland exerting pressure on the chiasma.
Lesion or destruction of the following structures could lead to contralateral homonymous hemianopia, except:
C) Optic nerve
Lesion or destruction of the optic nerve would lead to total blindness of one eye (monocular blindness).
Which of the following is not a normal finding when examining the ocular fundus?
A) The center of the optic disc is darker and hollowed out.
The center of the optic disc is paler and hollowed out.
True or False: In internal opthalmophlegia, the innervation of the extraocular muscles is spared with selective loss of the autonomic innervation of the sphincter pupillae and ciliary muscle.
True
Meanwhile, in external opthalmophlegia, the sphincter pupillae and the ciliary muscle are spared with paralysis of the extraocular muscles.
True or False: With traumatic lesions, internal opthalmophlegia is more common than external opthalmophlegia.
True
The possible explanation for the involvement of the autonomic nerves and the sparing of the remaining fibers is that the parasympathetic autonomic fibers are superficially placed within the oculomotor nerve and are likely to be first affected by compression.
True or False: Diabetic neuropathy is commonly associated with internal opthalmophlegia.
False
Diabetic neuropathy is commonly associated with external opthalmophlegia. In diabetic neuropathy, there is impaired nerve conduction. Consequently, the autonomic fibers are unaffected, whereas the nerves to the extraocular muscles are paralyzed.
True or False: Both the trochlear and abducent nerves are commonly bruised or stretched following head injuries.
True
Both the trochlear and abducent nerves are long and slender.
Which of the following is incorrect about internucelar opthalmophlegia?
B) When the patient is asked to look to the right or left, the ipsilateral medial rectus contracts, turning the eye medially, but the contralateral lateral rectus fails to contract, and the eye looks straight forward.
When the patient is asked to look to the right or left, the ipsilateral lateral rectuscontracts, turning the eye laterally, but the contralateral medial rectus fails to contract, and the eye looks straight forward.
In trigeminal neuralgia, the severe, stabbing pain over the face is of unknown cause. Pain is most commonly felt over the skin areas innervated by the ophthalmic and maxillary divisions of the trigeminal nerve.
B) Only the first statement is true.
Pain is most commonly felt over the skin areas innervated by the mandibular and maxillary divisions of the trigeminal nerve; only rarely is pain felt in the area supplied by the ophthalmic division.
The facial nerve may be injured or may become dysfunctional anywhere along its course from the brainstem to the face. Which of the following statements below is incorrect?
D) If the patient is excessively sensitive to sound in one ear, the lesion may involve the nerve to the auricular muscle, which arises from the facial canal.
If the patient is excessively sensitive to sound in one ear, the lesion may involve the nerve to the stapedius muscle, which arises from the facial canal. The resulting condition is known as hyperacusis.
A firm swelling of the parotid salivary gland is usually associated with impaired function of the ________ nerve is strongly indicative or a cancer of the parotid gland.
A) Facial
A firm swelling of the parotid salivary gland is usually associated with impaired function of the facial nerve is strongly indicative or a cancer of the parotid gland with involvement of the nerve within the gland.
True or False: In patients with a lesion of the facial nerve motor nucleus or the facial nerve itself, all the muscle on the affected side of the face will be paralyzed.
True
True or False: In patients with hemiplegia, the emotional movements of the face are usually preserved.
True
This indicates that the upper motor neurons controlling thesemimetic movements have a course separate from that of the main corticobulbar fibers. A lesion involving this separate pathway alone results in loss of emotional movements, but voluntary movements are preserved.
Vestibular nystagmus is an uncontrollable rhythmic oscillation of the eyes, and the fast phase is away from the side of the lesion. This form of nystagmus is essentially a disturbance in the reflex control of the extraocular muscles, which is one of the functions of the semicircular canals.
D) Both statements are true.
Normally, the nerve impulses pass reflexively from the canals through the vestibular nerve, the vestibular nuclei, and the medial longitudinal fasciculus, to the third, fourth, and sixth cranial nerve nuclei, which control the extraocular muscles.
Caloric tests involve raising and lowering the temperature in the external auditory meatus, which induces convection currents in the endolymph of which semicircular canal?
B) Lateral
True or False: Only bilateral temporal lobe lesions cause deafness.
True
True or False: Isolated lesions of the glossopharyngeal nerve are rare and usually also involve the vagus nerve.
True
True or False: The afferent neuron of the gag reflex runs in the glossopharyngeal nerve, and the efferent neurons run in the glosspharyngeal nerve and the vagus nerves.
True
In gag or pharyngeal reflex, touching the lateral wall of the pharynx with a spatula will cause the pharyngeal muscles to contract. The efferent neurons run in the glossopharyngeal nerve which supplies the stylopharyngeusmuscle and the vagus nerve which supplies the pharyngeal constrictor muscles.
True or False: All of the muscles of the larynx are supplied by the recurrent laryngeal branch of the vagus, except the cricothyroid muscle.
True
The cricothyroid muscle is supplied by the external laryngeal branch of the superior laryngeal branch of the vagus.
True of False: Lesions involving the vagus nerve in the middle cranial fossa commonly involve the glossopharyngeal, accessory, and hypoglossal nerves as well.
False
Lesions involving the vagus nerve in the posterior cranial fossa commonly involve the glossopharyngeal, accessory, and hypoglossal nerves as well.
Which of the following is incorrect about lesions of the spinal accessory nerve?
A) Weakness in turning the head towards the side of the lesion
It should be weakness in turning the head opposite to the side of the lesion. The sternocleidomastoid muscle laterally flexes the head to the same side and rotates it to the opposite side.
A part of the hypoglossal nucleus that supplies the genioglossus muscle receives corticonuclear fibers only from the ipsilateral cerebral hemisphere. If a patient has a lesion of the corticonuclear fibers, there will be no atrophy or fibrillation of the tongue, and on protrusion, the tongue will deviate to the same side.
C) Both statements are false.
A part of the hypoglossal nucleus that supplies the genioglossus muscle receives corticonuclear fibers only from the contralateral cerebral hemisphere. If a patient has a lesion of the corticonuclear fibers, there will be no atrophy or fibrillation of the tongue, and on protrusion, the tongue will deviate to the opposite side.
Note that the genioglossus is the muscle that pulls the tongue forward.
True or False: A lesion of the olfactory cortex cannot produce complete anosmia.
True
A lesion of the olfactory cortex cannot produce complete anosmia because both olfactory tracts communicate with each other through the anterior commissure.
True or False: Paralysis of the right superior oblique results from the lesion of the right trochlear nucleus.
False
Paralysis of the right superior oblique results from the lesion of the left trochlear nucleus, because the the trochlear nerves decussate on emergence from the midbrain.
Those cranial nerves that pass through relatively small foramina in the skull are likely to be compressed by the new bone growth in osteitis deformans. All of the following cranial nerves are likely to be compressed, except:
C) Trigeminal
The facial and vestibulocochlear nerves are commonly involved, following the narrowing of the internal acoustic meatus. The olfactory and optic nerves may also be involved as they pass through the cribriform plate and the optic canal, respectively.
True or False: There is no weakness and atrophy of trapezius muscles in hemiplegic patients.
True
The trapezius muscle is supplied by the spinal part of the accessory nerve. The spinal nucleus of this nerve in the upper five cervical segments of the spinal cord receive cortical fibers from both cerebral hemispheres; hence, there is no muscular weakness. For a muscle to atrophy (except for disuse atrophy), the integrity of the monosynaptic reflex arc must be destroyed.
True or False: The trigeminal and oculomotor nerves are commonly irritated by an aneurysm of the internal carotid artery.
True
The opthalmic division of the trigeminal nerve can be irritated by the slowly expanding aneurysm of the internal carotid artery as it is lying in the cavernous sinus. The oculumotor nerve can also be irritated as it is situated in the lateral wall of the cavernous sinus.
Which of the following is not true about the Argyll Robertson pupil?
A) The lesion destroys the accommodation reflexes of both eyes.
The lesion leaves the pathway for the accommodation reflex intact.
Describe the effects of a lesion at the following points along the visual pathway of the right eye:
1. Section of the right optic nerve
2. Midline section of the optic chiasma
3. Section of the right optic tract
4. Section of the right optic radiation
5. Destruction of the cortex of the right occipital pole
1. Section of the right optic nerve - complete blindness of the right eye
2. Midline section of the optic chiasma - bitemporal hemianopia
3. Section of the right optic tract - left homonymous hemianopia
4. Section of the right optic radiation - left homonymous hemianopia
5. Destruction of the cortex of the right occipital pole - left homonymous hemianopia, usually with some macular sparing owing to the large area of the cortex allotted to the macula
True or False: A lesion of the vagus nerve would result in the uvula being depressed to the opposite side.
False
A lesion of the vagus nerve would result in the uvula being elevated to the opposite side.
A 32-year old woman with syringomyelia was found on physical examination to have impairment of appreciation of pain and temperature of the face but preservation of light touch. Which sensory nucleus/nuclei of the trigeminal nerve is likely to be affected?
B) Spinal nucleus
The afferent fibers entering the central nervous system through the trigeminal nerve pass either to the main sensory nucleus in the pons or to the spinal nucleus in the medulla oblongata and the first two cervical segments of the spinal cord. In this patient, the lesion of syringomyelia was situated in the medulla and the cervical part of the spinal cord, affecting the spinal nucleus and leaving the main sensory nucleus intact.
True or False: The main motor and parasympathetic nuclei of the vagus nerve are controlled by both cerebral hemispheres; thus, hemiplegia will have no effect on the movement of the vocal cords.
True
The cranial nerve nuclei listed below have the following descending tracts terminating on them:
A) The nucleus of the facial nerve supplying the muscles of the lower part of the face receives only crossed corticobulbar tracts.
The inferior salivatory nucleus of the glosspharyngeal nerve receives descending tracts from the hypothalamus.
The trigeminal motor nucleus receives crossed and uncrossed corticobulbar tracts.
The nucleus of the trochlear nerve receives crossed and uncrossed corticobulbar tracts.
The nuclei associated with the facial nerve include the following:
B) Lacrimal nucleus
The inferior salivatory nucleus is part of the glossopharyngeal nuclei.
The nucleus ambiguus is the motor nucleus associated with 9th, 10th, and cranial part of the 11th cranial nerves.
The facial nerve has sensory nucleus for taste.
A patient with unilateral upper motor neuron paralysis of the facial muscles can smile with both side of his face in response to a joke but not voluntarily. This can be explained by the following facts:
D) The muscles producing mimetic movements of the face are innervated by corticobulbar fibers that have a course separate from the main corticobulbar fibers.
The main corticobulbar fibers controlling the movements of the voluntary facial muscles in this patient have been destroyed.
The reticular fibers, possibly originating in the hypothalamus and descending motor nuclei of the facial nerves, are intact.
The lower motor neurons of the facial nerve supplying the facial muscles are intact.
Which of the following structures participates in the reception of sound?
C) Trapezoid body
The cerebral cortex is necessary for which of the following visual reflexes?
A) Accommodation reflex
The nasal field of the right eye is projected to the:
B) Temporal retina of the right eye
The nasal field of the right eye is projected to the:
1. Temporal retina of the right eye
2. Right lateral geniculate body
3. Both banks of the right calcarine fissure
4. Right optic tract
5. Right optic radiation
Right pupillary constriction associated with light directed at the left eyes requires the:
D) Left optic nerve
The right oculomotor nerve is also required.
Select the lettered statement concerning the hypoglossal nerve that is correct:
C) A lesion involving the hypoglossal nerve will result in deviation of the tongue toward the same side as the lesion when the tongue is protruded.
The hypoglossal nerve emerges from the brainstem between the pyramid and the olive.
The hypoglossal nerve carries with it fibers from the first cervical nerve.
Select the lettered statement concerning the trigeminal nuclei that is correct:
B) Proprioceptive impulses from the muscles of mastication reach the mesencephalic nucleus along the fibers that are part of the unipolar neurons of the nucleus.
The main sensory nucleus lies within the pons.
The spinal nucleus extends inferiorly as far as the second cervical segment.
The trigeminal lemniscus contains only afferent fibers from the contralateral sensory nuclei of the trigeminal nerve.
The cranial nerves listed below are associated with the following functions:
C) The spinal part of the accessory nerve shrugs the shoulder.
The facial nerve supplies the orbicularis oculi muscle, which closes the eye.
The trigeminal nerve supplies the muscles of mastication responsible for chewing.
The glossopharyngeal nerve receives the sensation of touch from the posterior third of the tongue.
The following statements concern the cranial nerves involved in the process of vision:
B) The optic nerve is surrounded by an extension of the subarachnoid space.
The nerve fibers of the optic nerve are surrounded by oligodendrocytes.
Internal ophthalmophlegia is a condition in which the oculomotor nerve supply to the sphincter pupillae and the ciliary muscle is lost, but the innervation of the extraocular muscles is spared. Meanwhile, external ophthalmophlegia is a condition in which the oculomotor nerve supply to the extraocular muscles is lost, but the innervation of the sphincter pupillae and the ciliary muscle is spared.
The optic nerve leaves the orbital cavity through the optic canal in the lesser wing of the sphenoid bone.
The following statements concern the cranial nerves listed below:
A) The olfactory receptor cells are located in the mucus membrane of the nasal cavity above the level of the superior concha.
The main sensory nucleus of the trigeminal nerve lies in the brainstem lateral to the motor nucleus.
Proprioceptive impulses from the facial muscles end in the mesencephalic nucleus of the trigeminal nerve.
The facial nerve leaves the posterior cranial fossa with the vestibulocochlear nerve by passing through the internal acoustic meatus.
A 64-year old man visited his physician because he had noticed a swelling on the right side of his neck. He mentioned that he had suffered from a chronic cough for 6 months and was rapidly losing weight. On physical examination, the following possible signs emerged except:
C) The patient had no taste sensation on the anterior two-thirds of the tongue on the right side.
The taste sensation from the mucus membrane covering the anterior two-thirds of the tongue is conducted in the facial nerves and the chorda tympani nerves, which are a considerable distance from the metastases in the deep cervical lymph nodes in the neck.
A 64-year old man visited his physician because he had noticed a swelling on the right side of his neck. He mentioned that he had suffered from a chronic cough for 6 months and was rapidly losing weight. The physician made the following correct conclusions, except:
C) The tongue was wrinkled because the mucus membrane was atrophied.
Secondary to a lesion of the right hypoglossal nerve, the tongue muscles on the right side had atrophied and diminished in size, resulting in the wrinkling of the overlying normal mucus membrane.
The thalamus is subdivided into three main parts: the anterior, the medial, and the lateral parts. Which of the following statements below is incorrect?
C) None of these
The ventral posteromedial nucleus of the thalamus receives the descending trigeminal and gustatory pathways. Meanwhile, the ventral posterolateral nucleus receives the important ascending sensory tracts, the medial and spinal lemnisci.
C) Only the second statement is true.
The ventral posteromedial nucleus of the thalamus receives the ascending trigeminal and gustatory pathways.
Which of the following is not true about the medial geniculate body?
D) Its afferent fibers come from the superior colliculus and form the superior brachium.
Its afferent fibers come from the inferior colliculus and form the inferior brachium.
Which of the following is not true about the lateral geniculate body?
A) The afferent fibers leaving it form the visual radiation, which passes to the visual cortex of the occipital lobe.
The efferent fibers leaving it form the visual radiation, which passes to the visual cortex of the occipital lobe.
True or False: Every thalamic nucleus (except the reticular nucleus) sends axons to specific parts of the cerebral cortex, and every part of the cerebral cortex sends reciprocal fibers back to the thalamic nuclei.
True
Information received in the thalamus is always shared with the cerebral cortex. The cortex and thalamus can modify each other's activities.
True or False: A vast amount of sensory information of all types (except hearing) converges on the thalamus and presumably is integrated through the interconnections between the nuclei.
False
A vast amount of sensory information of all types (except smell) converges on the thalamus.
True or False: Following the removal of cortex, the thalamus can still appreciate discriminative sensations.
False
Following the removal of cortex, the thalamus can still appreciate crude sensations. However, the cerebral cortex is required for the interpretation of sensations based on past experiences.
The ventroanterior and the ventrolateral nuclei of the thalamus form part of the basal nuclei circuit and thus are involved in the performance of involuntary movement. These nuclei receive input from the globus pallidus and sends fibers to the prefrontal, supplemental, and premotor areas of the cerebral cortex.
B) Only the second statement is true.
The ventroanterior and the ventrolateral nuclei of the thalamus are involved in the performance of voluntary movement.
True or False: The reticular nuclei of the thalamus are closely related with the activities of the reticular formation; thus, they are able to influence the levels of consciousness and alertness.
False
The intralaminar nuclei of the thalamus are closely related with the activities of the reticular formation; thus, they are able to influence the levels of consciousness and alertness.
True or False: Cauterization of the midline nuclei of the thalamus can relieve severe and intractable pain associated with terminal cancer.
False
Cauterization of the intralaminar nuclei of the thalamus can relieve severe and intractable pain associated with terminal cancer.
Which of the following is not true about the thalamic pain?
D) Spontaneous pain, which is often excessive, occurs on the same side of the body.
Spontaneous pain, which is often excessive, occurs on the opposite side of the body.
All of the following are true about the thalamic hand, except:
C) The MCP joints are extended, while the IP joints are flexed.
The MCP jointsareflexed, while the IP joints are extended.
The following statements concern the thalamus:
C) All types of sensory information, with the exception of smell, reach the thalamic nuclei via afferent fibers.
The intralaminar nuclei of the thalamus are closely connected with the reticular formation.
The intralaminar nuclei influence the levels of consciousness and alertness.
The thalamus is covered on its superior surface by a thin layer of white matter called the stratum zonale.
The following statements concern the thalamus:
D) The cerebellar-rubro-thalamic-cortical-ponto-cerebellar neuron pathway is important in voluntary movement.
The corticostriatal-pallidal-thalamic-cortical neuron pathway is also important in voluntary movement.
The external medullary lamina is an area of white matter lying on the lateral surface of the thalamus.
The Y-shaped internal medullary lamina subdivides the thalamus into three main parts.
The ventral posteromedial nucleus receives the ascending trigeminal and gustatory pathways.
The following statements concern the medial geniculate body:
B) The medial geniculate body receives auditory information from the inferior colliculus and from the lateral lemniscus.
Afferent fibers from the medial geniculate body form the inferior brachium.
The medial geniculate body projects to the auditory cortex of the superior temporal gyrus.
The medial geniculate body is a swelling on the posterior surface of the thalamus.
The following statements concern the lateral geniculate body:
A) The lateral geniculate body has a nucleus made up of six layers of nerve cells.
The lateral geniculate body receives most of the fibers of the optic tract.
The lateral geniculate body is a swelling on the undersurface of the pulvinar of the thalamus.
The afferent fibers to the lateral geniculate body are the axons of the ganglion cells of the retina.
Which of the following is not true about the hypothalamus?
C) It directly controls body homeostasis.
It indirectly controls body homeostasis.
All of the following hypothalamic nuclei are found in the medial zone, except:
B) Lateral nucleus
In the medial zone, the following hypothalamic nuclei can be recognized, from anterior to posterior:
1. part of the pre-optic nucleus
2. anterior nucleus
3. part of suprachiasmatic nucleus
4. paraventricular nucleus
5. dorsomedial nucleus
6. ventromedial nucleus
7. infundibular (arcuate) nucleus
8. posterior nucleus
All of the following hypothalamic nuclei are found in the lateral zone, except:
A) Pre-optic
Although a part of the pre-optic nucleus is found in the lateral zone, some part of it is also found in the medial zone.
In the lateral zone, the following hypothalamic nuclei can be recognized, from anterior to posterior:
1. part of pre-optic nucleus
2. part of suprachiasmatic nucleus
3. supraoptic nucleus
4. lateral nucleus
5. tuberomammillary nucleus
6. lateral tuberal nuclei
From which lobe of the cerebral hemisphere do the corticohypothalamic fibers originate?
D) Frontal
True or False: The hypothalamus is connected to the hypophysis cerebri by two pathways.
True
Hypophysis cerebri is also known as the pituitary gland. The two pathways are the:
1. Nerve fibers that travel from the supraoptic and paraventricular nuclei to the posterior lobe of the hypophysis
2. Long and short portal blood vessels that connect sinusoids in the median eminence and infundibulum with capillary plexuses in the anterior lobe of the hypophysis
True or False: The hormones vasopressin and oxytocin are synthesized in the nerve cells of the supraoptic and paraventricular nuclei of the hypothalamus.
True
Vasopressin (antidiuretic hormone) is produced mainly in the supraoptic nucleus, whereas oxytocin is mainly produced in the paraventricular nuclei.
True or False: The supraoptic nucleus, which mainly produces vasopressin, acts as a baroreceptor.
False
The supraoptic nucleus, which mainly produces vasopressin, acts as a osmoreceptor. Should the osmotic pressure of the blood circulating through the nucleus be too high, the nerve cells increase their production of vasopressin, and the antidiuretic effect of this hormone will increase reabsorption of water from the kidney.
True or False: When the baby suckles at the breast, a nervous reflex from the nipple stimulates the hypothalamus to produce more oxytocin.
True
Oxytocin stimulates the contraction of myoepithelial cells that surround the alveoli and ducts of the breast.
The hormones vasopressin and oxytocin are passed along the axons of the supraoptic and paraventricular nuclei together with carrier proteins called _______ and are released at the axon terminals.
C) Neurophysins
True or False: Neurosecretory cells situated mainly in the lateral zone of the hypothalamus are responsible for the production of the releasing hormones and release-inhibiting hormones.
False
Neurosecretory cells situated mainly in the medial zone of the hypothalamus are responsible for the production of the releasing hormones and release-inhibiting hormones.
True or False: The anterior and the preoptic nuclei of the hypothalamus influence parasympathetic responses, while the posterior and the lateral nucleui influence the sympathetic responses.
True
In the hypothalamus, there exist areas that might be termed parasympathetic and sympathetic centers. However, it has been shown that considerable overlap of function occurs in these areas.
The pituitary releasing and release-inhibiting factors have presumed nuclear origin in the hypothalamus. Which of the following pairs below is incorrectly matched?
B) Luteinizing hormone-releasing hormone: preoptic and posterior nuclei
Luteinizing hormone-releasing hormone is presumed to originate from the pre-optic and the anterior nuclei.
Each hypothalamic nuclei has a distinct function. Which of the following statements below is incorrect?
C) The posterior hypothalamic nucleus controls the parasympathetic system.
The posterior and lateral hypothalamic nuclei control the sympathetic system.
True or False: Bilateral destruction of the medial hypothalamic nuclei results in anorexia, with consequent loss in body weight.
False
The medial hypothalamic nucleus is referred to as the satiety center. Bilateral destruction of this structure produces an uncontrolled voracious appetite, causing extreme obesity.
The suprachiasmatic nucleus, which receives afferent fibers from the iris, plays an important role in controlling biologic rhythms. Nerve impulses generated in response to variations in the intensity of light are transmitted via this nucleus to influence the activities of many hypothalamic nuclei.
C) Only the second statement is true.
The suprachiasmatic nucleus receives afferent fibers from the retina.
Chief center of the brain for maintaining the internal milieu of the body
B) Hypothalamus
Frohlich syndrome may occur secondary to a chromophobe adenoma of the anterior lobe of the hypophysis. All of the following are possible manifestations of this condition, except:
C) Accummulation of fat in the trunk, especially in the middle part of the abdomen
Frohlich syndrome may manifest with the following signs and symptoms:
1. Bitemporal hemianopia - The tumor caused gradual erosion of the sella turcica of the skull, compressing the optic chiasma.
2. Headache and attacks of vomiting - The tumor resulted in increased intracranial pressure.
3. Hypogonadism and absence of secondary sex characteristics - The tumor pressed on the hypothalamus, resulting to its loss of control on the anterior lobe of the hypophysis.
4. Accumulation of fat in the trunk, especially in the lower part of the abdomen - The tumor pressed on the hypothalamus.
True or False: A lesion of the posterior lobe of the hypophysis is usually followed by diabetes insipidus.
False
A lesion of the posterior lobe of the hypophysis is not usually followed by diabetes insipidus, since the vasopressin produced by the neurons of the supraoptic nucleus escapes directly into the bloodstream.
True or False: Hydrocephalus, caused by blockage of the three foramina in the roof of the fourth ventricle or by blockage of the cerebral aqueduct, may compress the hypothalamus.
True
Hydrocephalus, caused by blockage of the three foramina in the roof of the fourth ventricle or by blockage of the cerebral aqueduct, will result in a rise in pressure in the third ventricle. The hypothalamus may be compressed as it is situated in the floor and lower part of the lateral walls of the third ventricle.
Main subcortical center regulating the parasympathetic and sympathetic parts of the autonomic system
C) Hypothalamus
The following statements concern the hypothalamus:
A) The nuclei of the hypothalamus are divided by an imaginary plane formed by the columns of the fornix and the mammillothalamic tract into medial and lateral groups.
It lies below the thalamus and not in the tectum of the midbrain.
The suprachiasmatic nucleus receives nerve fibers from the retina.
The lateral boundary of the hypothalamus is formed by the internal capsule.
The following statements concern the hypothalamus:
B) The blood-brain barrier is absent in the median eminence of the hypothalamus, thus permitting the neurons to sample the chemical content of the plasma directly.
When seen from the inferior aspect, the hypothalamus is related to the following structures, from anterior to posterior: the optic chiasma, the tuber cinereum, and the mammillary bodies.
The mammillary body overlaps the medial and lateral groups of the hypothalamic nuclei.
The preoptic area of the hypothalamus is located between the lamina terminalis and the optic chiasma.
The following statements concern the afferent fibers passing to the hypothalamus:
B) The hypothalamus receives many afferent fibers from the viscera via the reticular formation.
Fibers pass from the hippocampus to the mammillary bodies, bringing information from the limbic system.
Olfactory impulses reach the hypothalamus through the medial forebrain bundle.
The pineal gland does not send fibers to the hypothalamus.
The following statements concern the hypothalamus:
A) The nerve cells of the hypothalamus produce releasing and release-inhibiting hormones that control the production of various hormones in the anterior lobe of the hypohysis.
Somatic afferent fibersenter the hypothalamic nuclei via the medial and spinal lemnisci.
The anterior portion of the hypothalamus controls those mechanisms that dissipate heat loss.
The hunger center is probably located in the lateral region of the hypothalamus.
The following statements concern the functional activities of the hypothalamus:
A) The hypothalamus brings about the physical changes associated with emotion, such as increased heart rate and flushing or pallor of the skin.
The lateral hypothalamic nuclei are concerned with fluid intake.
The corticotropin-releasing hormone is produced in the paraventricular nuclei of the hypothalamus.
The hypothalamus controls the lower autonomic centers by means of pathways through the reticular formation.
The following statements concern the hypothalamohypophyseal tract:
D) The nerve cells of the supraoptic and paraventricular nuclei produce the hormones vasopressin and oxytocin.
The hormones travel in the axons with protein carriers called neurophysins.
Vasopressin stimulates the distal convoluted tubules of the kidney, causing increased absorption of water from the urine.
The hormones are absorbed into the bloodstream in the capillaries of the posterior lobe of the hypophysis.
The following statements concern the hypophyseal portal system:
A) The production of the releasing and release-inhibiting hormones can be influenced by the level of the hormone produced by the target organ controlled by the hypophysis.
The blood vessels commence superiorly in the median eminence and end inferiorly in the vascular sinusoids of the anterior lobe of the hypophysis.
Afferent nerve fibers entering the hypothalamus influence the production of the releasing hormones by nerve cells.
The neuroglial cells of the hypothalamus are not responsible for the production of the release-inhibiting hormones.
True or False: Sympathetic and parasympathetic divisions of the autonomic nervous system are considered as physiologic antagonists.
True
Sympathetic and parasympathetic divisions of the autonomic nervous system produce opposite effects in most organs and are thus considered as physiologic antagonists.
Which of the following is not true about the sympathetic part of the autonomic nervous system?
D) It inhibits the smooth muscle contraction of the bronchi, intestine, and sphincters.
It inhibits the smooth muscle contraction of the bronchi, intestine, and bladder wall.
The lateral gray columns of the spinal cord from the ____ thoracic segment to the ____ lumbar segment possess the cell bodies of the sympathetic connector neurons.
C) First, second
Sometimes, the third lumbar segment also possess a cell body of the sympathetic connector neuron.
The sympathetic trunks are two ganglionated nerve trunks that extend the whole length of the vertebral column. Which of the following statements below is incorrect?
D) In the neck, each trunk has 2 ganglia.
In the neck, each trunk has 3 ganglia.
Which of the following is not true about the sympathetic trunks?
C) In the thorax, the trunks lie anterior to the tubercles of the ribs or lie on the sides of the vertebral bodies.
In the thorax, the trunks lie anterior to the heads of the ribs or lie on the sides of the vertebral bodies.
True or False: The ratio of preganglionic to postganglionic fibers in the sympathetic division of the autonomic system is 1:10, whereas it is only 1:3 or less in the parasympathetic division.
True
Thus, the sympathetic division permits a wider control of involuntary structures.
All of the following are cranial parasympathetic ganglia, except:
D) Sublingual
It should be submandibular.
The ganglion cells of the parasympathetic division are placed in the following nerve plexuses, except:
A) Mesenteric
The ganglion cells of the parasympathetic division are placed in the following nerve plexuses:
1. Cardiac
2. Pulmonary
3. Myenteric (Auerbach)
4. Mucosal (Meissner)
5. Hypogastric
True or False: The parasympathetic postganglionic fibers are myelinated and of relatively long length compared with sympathetic postganglionic fibers.
False
The parasympathetic postganglionic fibers are unmyelinated and of relatively short length compared with sympathetic postganglionic fibers.
Which of the following is not true about the autonomic plexuses?
A) None of these
In the abdomen, the plexuses are associated with the aorta and its branches, and subdivisions of these autonomic plexuses are named according to the branch of the aorta along which they are lying.
Which of the following is not true about the autonomic ganglion?
D) Its preganglionic fibers are unmyelinated, small, and relatively slow-conducting B fibers.
Its preganglionic fibers are myelinated, small, and relatively slow-conducting B fibers. Its postganglionic fibers are unmyelinated, smaller, and slower-conducting C fibers.
Synaptic transmitter that excites the postganglionic neuron in both sympathetic and parasympathetic ganglia
C) Acetylcholine
All of the following are true about the acetycholine receptors, except:
A) In preganglionic neurons, both sympathetic and parasympathetic, the release of acetylcholine binds predominantly with the muscarinic receptors on the postganglionic neurons.
In preganglionic neurons, both sympathetic and parasympathetic, the release of acetylcholine binds predominantly with the nicotinic receptors on the postganglionic neurons.
The acetylcholine traverses the synaptic cleft and binds reversibly with the cholinergic (muscarinic) receptor on the post-synaptic membrane of the effector cell. Within 2 to 3 msec, it is hydrolyzed into acetic acid and choline by the enzyme acetylcholinesterase.
B) Both statements are true.
The acetylcholinesterase is located on the surface of the nerve and receptor membranes.
True or False: After the acetylcholinesterase has broken down the acetylcholine into acetic acid and choline, the acetic acid is reabsorbed into the nerve ending and is used again for the synthesis of acetylcholine.
False
The choline is reabsorbed into the nerve ending and is used again for the synthesis of acetylcholine.
True or False: Postganglionic nerve endings, particularly those that end on the cells of sweat glands and blood vessels in skeletal muscle, release norepinephrine.
False
Postganglionic nerve endings, particularly those that end on the cells of sweat glands and blood vessels in skeletal muscle, release acetylcholine, which binds with muscarinic receptors on the postsynaptic membrane.
True or False: Norepinephrine has a greater effect on alpha receptors than on beta receptors.
True
True or False: As a general rule, the alpha receptor sites are associated with most of the excitatory functions of the sympathetic system, whereas the beta receptor sites are associated with most of the inhibitory functions.
True
The action of norepinephrine on the receptor site of the effector cell is terminated by reuptake into the nerve terminal, where it is stored in presynaptic vesicles for reuse. Some of the norepinephrine escapes from the synaptic cleft into the general circulation and is subsequently metabolized in the kidney.
B) Only the first statement is true.
Some of the norepinephrine escapes from the synaptic cleft into the general circulation and is subsequently metabolized in the liver.
True or False: Atropine competitively agonizes the muscarinic action by occupying the cholinergic receptor sites on the effector cells.
False
Atropine competitively antagonizes the muscarinic action by occupying the cholinergic receptor sites on the effector cells.
True or False: Propanolol inhibits the synthesis and storage of norepinephrine at sympathetic endings.
False
Reserpine inhibits the synthesis and storage of norepinephrine at sympathetic endings.
_________ is regarded as a higher nervous center for the control of the lower autonomic centers in the brainstem and spinal cord.
B) Hypothalamus
Contractions of the smooth muscle in the gut wall can occur in the absence of myenteric plexus. However, the coordinated purposeful contractions, as seen with peristalsis and segmental movements, requires the presence of this plexus.
A) Both statements are true.
The myenteric and mucosal plexuses found in the gastrointestinal tract are isolated from the central nervous system.
The sympathetic efferent nerve fibers originate from nerve cells in the anterior gray column of the spinal cord between the first thoracic and second lumbar segments. Meanwhile, the parasympathetic efferent nerve fibers originate from nerve cells in the 5th, 7th, 9th, and 10th cranial nerves and in the gray matter of 2nd, 3rd, and 4th sacral segments.
C) Both statements are false.
The sympathetic efferent nerve fibers originate from nerve cells in the lateral gray column of the spinal cord. The parasympathetic efferent nerve fibers originate from nerve cells in the 3rd, 7th, 9th, and 10th cranial nerves.
The sympathetic ganglia are located either in the paravertebral sympathetic trunks or in the prevertebral ganglia. Meanwhile, the parasympathetic ganglia are located close to the viscera or within plexuses within the viscera.
C) Both statements are true.
Which of the following is not true about the divisions of the autonomic nervous system?
A) Norepinephrine is liberated at all sympathetic postganglionic endings, whereas acetylcholine is liberated at all parasympathetic postganglionic endings.
Norepinephrine is liberated at most sympathetic postganglionic endings, whereas acetylcholine is liberated at all parasympathetic postganglionic endings and at few postganglionic sympathetic endings.
True or False: The sympathetic division of the autonomic nervous system has a widespread action on the body, while the parasympathetic division has a more discrete control.
True
The sympathetic division of the autonomic nervous system has a widespread action on the body as the result of the preganglionic fibers synapsing on many postganglionic neurons and the suprarenal medulla releasing the sympathetic transmitters epinephrine and norepinephrine, which are distributed throughout the body through the bloodstream. The parasympathetic division has a more discrete control, since the preganglionic fibers synapse on only a few postganglionic neurons and there is no comparable organ to the suprarenal medulla.
True or False: The major part of levator palpebrae superioris is formed by skeletal muscles innervated by the oculomotor nerve.
True
A small part of it is composed of smooth muscle fibers innervated by sympathetic postganglionic fibers from the superior sympathetic ganglia.
The dilator pupillae is supplied by parasympathetic fibers from the Edinger-Westphal nucleus of the oculomotor nerve. Meanwhile, the constrictor pupillae is supplied by postganglionic fibers from the superior cervical sympathetic ganglion.
C) Both statements are false.
The constrictor pupillae is supplied by parasympathetic fibers from the Edinger-Westphal nucleus of the oculomotor nerve. Meanwhile, the dilator pupillae is supplied by postganglionic fibers from the superior cervical sympathetic ganglion.
Which of the following pairs below is incorrectly matched?
A) Dilator pupillae: ciliary ganglion
It should be constrictor pupillae: ciliary ganglion.
True or False: Stimulation of sympathetic postganglionic fibers in the heart results in dilatation of the coronary arteries.
True
The coronary dilatation is mainly produced in response to local metabolic needs rather than by direct nerve stimulation of the coronary arteries.
True or False: Gallbladder disease can refer pain to the right shoulder.
True
The gallbladder and biliary ducts receive postganglionic parasympathetic and sympathetic fibers from the hepatic plexus. Some of the autonomic fibers join the right phrenic nerve.
True or False: There is no parasympathetic innervation of the medulla of the suprarenal gland.
True
True or False: The sympathetic nerves to the detrusor muscle have little or no action on the smooth muscle of the bladder wall and are distributed mainly to the blood vessels.
True
The sympathetic nerves to the sphincter vesicae of the urinary bladder play only a minor role in maintaining urinary continence. However, in the male, the sympathetic innervation of this sphincter causes active contraction of the bladder neck during ejaculation to prevent the seminal fluid from entering the bladder.
D) Both statements are true.
True or False: The initial vascular engorgement seen in penile erection is controlled by the parasympathetic part of the autonomic nervous system.
True
The parasympathetic fibers from the gray matter of the 2nd, 3rd, and 4th sacral segments cause vasodilatation of the arteries and greatly increase the blood flow to the erectile tissue.
True or False: Sympathetic innervation to the uterus may cause uterine contraction and vasoconstriction.
True
Although the uterine muscle is largely under hormonal control, sympathetic innervation may cause uterine contraction and vasoconstriction, whereas parasympathetic fibers have the opposite effect.
True or False: The preganglionic fibers of the sympathetic nerves supplying the arteries of the upper limb originate from the cell bodies in the second to the eighth thoracic segments of the spinal cord.
True
True or False: The preganglionic fibers of the sympathetic nerves supplying the arteries of the lower limb originate from cell bodies in the lower three thoracic and upper two or three lumbar segments of the spinal cord.
True
The afferent fibers from the aortic arch ascend in the glossopharyngeal nerve and terminate in the nucleus solitarius. Meanwhile, the afferent fibers from the carotid sinus ascend in the vagus nerve and terminate in the dorsal nucleus.
D) Both statements are false.
The afferent fibers from the carotid sinus ascend in the glossopharyngeal nerve, whereas those from the aortic arch ascend in the vagus nerve. Both the carotid sinus and the aortic arch serve as baroreceptors.
Which of the following is not true about the Bainbridge reflex?
C) None of these
Which cranial nerve can be compressed by aneurysms in the junction between the posterior cerebral artery and the posterior communicating artery?
A) Oculomotor
Surface aneurysmal compression characteristically causes dilatation of the pupil and loss of the visual light reflexes.
The motor fibers in the facial nerve can be damaged by fractures of the skull involving the temporal bone. The vestibulocochlear nerve is closely related to the facial nerve in the external acoustic meatus, so clinical findings involving both nerves are common.
A) Both statements are false.
The autonomic fibers in the facial nerve can be damaged by fractures of temporal bone. The vestibulocochlear nerve may also be involved as it also passes through the internal acoustic meatus.
The glossopharyngeal and vagus nerves are at risk in stab and bullet wounds of the neck. The parasympathetic secremotor fibers to the sublingual salivary gland leave the glossopharyngeal nerve just below the skull; therefore, they are rarely damaged.
D) Only the first statement is true.
The parasympathetic secremotor fibers to the parotid salivary gland leave the glossopharyngeal nerve just below the skull; therefore, they are rarely damaged.
True or False: The sympathetic outflow in the sacral region of the spinal cord may be damaged in cauda equina injuries, leading to disruption of bladder, rectal, and sexual functions.
False
The parasympathetic outflow in the sacral region of the spinal cord may be damaged in cauda equina injuries, leading to disruption of bladder, rectal, and sexual functions.
All of the following are clinical features of autonomic dysfunction seen in diabetes mellitus, except:
D) Hypertension
It should be postural hypotension.
Horner syndrome consists of the following manifestations, except:
D) Mydriasis
Horner syndrome consists of:
1. Miosis (constriction of the pupil)
2. Anhydrosis (loss of sweating)
3. Ptosis (drooping of the eyelids)
4. Enophthalmos
5. Dilation of skin arterioles
All of the following are possible causes of Horner syndrome, except:
D) None of these
Horner syndrome results from the interruption of the sympathetic nerve supply to the head and neck. Pathologic causes include lesions in the brainstem or cervical part of the spinal cord that interrupt the reticulospinal tracts descending from the hypothalamus to the sympathetic outflow in the lateral gray column of T1 segment. Such lesions include multiple sclerosis and syringomyelia. Traction on the stellate ganglion due to a cervical rib or involvement of the ganglion in a metastatic lesion may interrupt the peripheral part of the sympathetic pathway.
All patients with Horner syndrome have miosis and ptosis. However, a distinction should be made between lesion occuring at the first-, second-, and third-order neurons of the sympathetic pathway. Which of the following statements regarding such distinctions is not true?
A) None of these
The presence or absence of other localizing signs and symptoms may assist in differentiating the three types of Horner syndrome.
Argyll Robertson pupil is characterized by a small pupil, which is of fixed size and does not react to accommodation but does contract with light. It is usually caused by a neurosyphilitic lesion interrupting the fibers that run from the pretectal nucleus to the Edinger-Westphal nuclei of the oculomotor nerve on both sides.
B) Only the second statement is true.
Argyll Robertson pupil is characterized by a small pupil, which is of fixed size and does not react to light but does contract with accommodation. The fact that the pupil constricts with accommodation implies that the connections between the parasympathetic nuclei and the constrictor pupillae muscle of the iris are intact.
All of the following are manifestations of Adie tonic pupil syndrome, except:
C) None of these
Adie tonic pupil is a benign syndrome, which probably results from a disorder of the parasympathetic innervation of the constrictor pupillae muscle.
True or False: Adie tonic pupil can be distinguished from Argyll-Robertson pupil by administering anticholinergic agents.
False
Adie tonic pupil can be confirmed by looking for hypersensitivity to cholinergic agents. Drops commonly used for this test are 2.5% methacholine (Mecholyl) or 0.1% pilocarpine. The Adie tonic pupil should constrict when these drops are put in the eye. These cholinergic agents do not cause pupillary constriction in mydriasis caused by oculomotor lesion or in drug-related mydriasis.
Which of the following is true about the Frey syndrome?
A) All of these
During the process of regeneration of the facial nerve, parasympathetic fibers normally destined for the submandibular and sublingual salivary glands are diverted to the lacrimal gland. Name the resulting complication.
B) Crocodile tears
In crocodile tears, watering of the eyes becomes associated with salivation.
Hirschsprung disease is a congenital condition in which there is failure of development of the mucosal (Meissner) plexus in the distal part of the colon. The involved part of the colon has no parasympathetic ganglion cells, and peristalsis is absent.
C) Only the second statement is true.
Hirschsprung disease (megacolon) is a congenital condition in which there is failure of development of the myenteric (Auerbach) plexus in the distal part of the colon.
True or False: In Hirschsprung disease, the distal part of the colon becomes enormously distended.
False
In Hirschsprung disease, the absence of myenteric plexus in the distal part of the colon blocks the passage of the feces into this region; thus, the proximal part of the colon becomes enormously distended.
True or False: The atonic bladder occurs during the phase of the spinal shock immediately following the injury and may last from a few days to several weeks.
True
The bladder wall muscle is relaxed, the sphincter vesicae is tightly contracted, and the sphincter urethrae is relaxed.
Which of the following is not true about the automatic reflex bladder?
A) Stretch receptors in the bladder wall are stimulated as the bladder fills, and the efferent impulses pass to the spinal cord.
Stretch receptors in the bladder wall are stimulated as the bladder fills, and the afferent impulses pass to the spinal cord. Efferent impulses pass down to the bladder muscle, which contracts; the sphincter vesicae and the urethral sphincter both relax.
Which of the following is not true about the autonomous bladder?
C) The bladder has no reflex control, but has voluntary control.
The bladder has no reflex control or voluntary control.
The involuntary internal anal sphincter is innervated by the postganglionic sympathetic fibers from the inferior mesenteric plexuses. Meanwhile, the voluntary external anal sphincter is innervated by the inferior rectal nerve.
B) Only the second statement is true.
The involuntary internal anal sphincter is innervated by the postganglionic sympathetic fibers from the hypogastric plexuses.
The final ejection of the fluid from the penis is the result of the rhythmic contraction of the bulbospongiosus muscles, which compress the urethra. This muscle is innervated by the:
A) Pudendal nerve
Discharge of the seminal fluid into the urinary bladder is prevented by the contraction of the sphincter vesicae, which is innervated by the:
B) Sympathetic nerves (L1-2)
The botulinum toxin binds reversibly to the nerve plasma membranes and prevents the release of acetylcholine at cholinergic synapses and neuromuscular junctions. Meanwhile, the black widow spider venom causes a brief release of acetylcholine at the nerve endings followed by a permanent blockade.
A) Only the second statements is true.
The botulinum toxin binds irreversibly to the nerve plasma membranes
Physostigmine, neostigmine, pyridostigmine, and carbamate and organophosphate insecticides are effective acetylcholinesterase inhibitors. Their use results in an excessive stimulation of the cholinergic receptors, producing the "SLUD" syndrome.
D) Both statements are true.
SLUD syndrome stands for salivation, lacrimation, urination, and defecation.
In mild cases of Raynaud disease, the treatment is avoidance of cold and smoking. In more severe cases, drugs that inhibit the parasympathetic activity, such as the reserpine, are used.
B) Only the second statement is true.
In more severe cases of Raynaud disease, drugs that inhibit the sympathetic activity, such as the reserpine, bring about arterial vasodilatation with consequent increase in blood flow to the fingers.
Lumbar preganglionic sympathectomy may be used to treat intermittent claudication. It is performed by removing the upper three lumbar ganglia and the intervening part of the sympathetic trunk.
C) Both statements are true.
Intermittent claudication, which is common in mean, is due to arterial occlusive disease of the leg. Lumbar preganglionic sympathectomy may be advocated as a form of treatment in order to bring about vasodilatation and an increase in blood flow through the collateral circulation.
A 35-year old man was getting off the back of a truck when it started to move. Having placed his feet on the ground, he grabbed a rail on the truck with his right hand and held on. The truck continued along the road for one block before it stopped. In the meantime, the man had been dragged along the road as he held onto the truck. He was seen in the emergency department in a state of shock, with cuts and abrasions to his legs. On careful examination, it was noted that the pupil of his right eye was constricted, and there was drooping of the right upper eyelid. The right eyeball seemed to be less prominent than the left. The skin of the right cheek felt warmer and drier and was redder in color than the left cheek. What condition does this patient is likely manifesting?
A) Preganglionic Horner syndrome
A 3-year old boy with a history since infancy of chronic constipation and abdominal distention was taken to a pediatrician. The child's mother said that the constipation was getting progressively worse. It was not responding to laxatives, and she was finding it necessary to give her son an enema once a week to relieve his abdominal distention. On physical examination, the child's abdomen was obviously distended, and a dough-like mass could be palpated along the course of the descending colon in the left iliac fossa. Examination of the rectum showed it to be empty and not dilated. Following an enema and repeated colonic irrigation with saline solution, the patient was given a barium enema followed by radiographic examination. The radiograph showed grossly distended descending colon and an abrupt change in lumen diameter where the descending colon joined the sigmoid colon. It was interesting to note that the child failed to empty the colon of barium. What is the likely diagnosis of this child?
A) Hirschsprung disease
This child had Hirschsprung disease, a congenital condition in which there is failure of development of the myenteric (Auerbach) plexus in the distal part of the colon. The proximal part of the colon is normal but becomes greatly distended due to the accumulation of feces. In this patient, the lower sigmoid colon, later at operation, was shown to have no parasympathetic ganglion cells. Thus, this segment of the bowel had no peristalsis and effectively blocked the passage of feces.
Which of the following is not true regarding the manifestations of Raynaud disease?
A) The cyanosis that follows is due to local capillary constriction due to accumulation of metabolites.
The cyanosis that follows is due to local capillary dilatation due to accumulation of metabolites. Since there is no blood flow through the capillaries, deoxygenated hemoglobin accumulates within them. It is during this period of prolonged cyanosis that the patient experiences severe, aching pain.
An obese 45-year old mother of six children was examined by her physician because her symptoms were suggestive of gallbladder disease. She complained of having severe attacks of colicky pain beneath the right costal margin, which often radiated through to the back beneath the right scapula. The referred pain can be explained by the fact that the pain afferent fibers from the smooth muscle wall of the cystic or bile duct pass through the celiac ganglia and ascend in the greater splanchnic nerve to enter the ________ segments of the spinal cord.
B) T5-T9
The pain was referred to the fifth through the ninth thoracic dermatomes on the right side.
Examination of a patient with neurosyphilis indicated that the pupil of her left eye was small and fixed and did not react to light but contracted when she was asked to look at a near object. What is the likely diagnosis of this patient?
A) Argyll-Robertson pupil
What transmitter substances are liberated at the following nerve endings:
1. Preganglionic sympathetic
2. Preganglionic parasympathetic
3. Postganglionic parasympathetic
4. Postganglionic sympathetic fibers to the heart muscle
5. Postganglionic sympathetic fibers to the sweat glands of the hand
1. Preganglionic sympathetic - acetylcholine
2. Preganglionic parasympathetic - acetylcholine
3. Postganglionic parasympathetic - acetylcholine
4. Postganglionic sympathetic fibers to the heart muscle - norepinephrine
5. Postganglionic sympathetic fibers to the sweat glands of the hand -acetylcholine
The following statements concern the autonomic nervous system:
B) The enteric nervous system is made up of the submucous plexus of Meissner and the myenteric plexus of Auerbach.
The nerve cells and the nerve fibers in the enteric nervous system are surrounded by neuroglia-like cells that closely resemble astrocytes.
C) The activities of the parasympathetic part of the autonomic nervous system are used to conserve and restore energy.
D) The pretectal nucleus is concerned with the light reflexes.
The following statements concern the autonomic nervous system:
A) White rami communicantes are found in the thoracic and first and second lumbar parts of the sympathetic trunk.
The greater splanchnic nerves are formed of myelinated axons.
The lesser splanchnic nerves arise from the 10th and 11th ganglia of the thoracic part of the sympathetic trunks.
The following general statements concern the autonomic nervous system:
D) Pain arising in the gastrointestinal tract is referred to the midline.
The cerebral cortex can influence the autonomic nervous system.
A patient with Adie tonic pupil syndrome has decreased or absent light reflex and a slow or delayed pupillary contraction to a near vision and a slow or delayed dilatation in the dark.
Visceral pain frequently is referred to skin areas that are innervated by same segments of the spinal cord as the painful viscus.
The following statements concern the Horner syndrome:
B) The patient has vasodilation of the facial skin arterioles.
There is ptosis of the upper eyelid and the pupil is constricted.
There is absence of facial sweating.
There is enophthalmos.
The sympathetic outflow:
C) is restricted to the T1-L2 segments of the spinal cord
Norepinephrine is secreted at the endings of the:
C) Postganglionic sympathetic fibers
The parasympathetic innervation controlling the parotid salivary gland arises from the:
B) Glossopharyngeal nerve
Which of the following statements best describes the parasympathetic part of the autonomic nervous system?
C) Effects are local and discrete due to preganglionic neurons synapsing with few postganglionic neurons.
Anticholinesterase drugs act at synapses by:
D) Blocking the breakdown of acetylcholine
Atropine has the following effect on the autonomic nervous system:
A) It blocks the action of acetylcholine on effector sites in the parasympathetic system.
The parasympathetic outflow in the spinal cord occurs at levels:
B) S2-4
The following statements concern autonomic innervation of the urinary bladder?
D) The afferent fibers from the bladder reach the spinal cord at the first and second lumbar segments and the second, third, and fourth sacral segments.
The sphincter urethrae is not under the control of the autonomic nervous system; it is made to contract voluntarily by the internal pudendal nerve.
The sympathetic part in the male causes contraction of the sphincter vesicae and prevents the reflux of semen into the bladder during ejaculation.
The sympathetic part innervates the blood vessels supplying the bladder wall.
The following statements concern the autonomic innervation of the heart:
C) The sympathetic nerves cause cardiac acceleration and increased force of contraction of the heart.
The parasympathetic part causes constriction of the coronary arteries.
The postganglionic fibers terminate on the sinoatrial and atrioventricular nodes.
The local metabolic needs of the cardiac muscle exert a greater control over the degree of dilation of the coronary arteries than the neural control of the arteries.
Match the numbered glands with the most appropriate lettered autonomic ganglion listed below. Each lettered option may be selected once, more than once, or not at all.
1. Submandibular gland a.) Otic ganglion
2. Lacrimal gland b.) Submandibular ganglion
3. Nasal gland c.) Pterygopalatine ganglion
4. Parotid gland d.) Ciliary ganglion
5. Sublingual gland e.) None of the above
1. Submandibular gland - submandibular ganglion
2. Lacrimal gland - pterygopalatine ganglion
3. Nasal gland - pterygopalatine ganglion
4. Parotid gland - otic ganglion
5. Sublingual gland - submandibular ganglion
Match the numbered autonomic ganglia with the most appropriate lettered viscus or muscle listed below. Each lettered option may be selected once, more than once, or not at all.
1. Superior cervical ganglion a.) Levator palpebrae superioris
2. Ciliary ganglion (smooth muscle only)
3. Celiac ganglion b.) Vermiform appendix
4. Inferior mesenteric ganglion c.) Constrictor pupillae
5. Superior mesenteric ganglion d.) Descending colon
e.) None of the above
1. Superior cervical ganglion - levator palpebrae superior (smooth muscle only)
2. Ciliary ganglion - constrictor pupillae
3. Celiac ganglion - none of the above; smooth muscle of the gut from gastroesophageal junction down to the middle of the second part of the duodenum; liver, pancreas, and spleen
5. Superior mesenteric ganglion- vermiform appendix
Match the numbered cranial nerves with the appropriate lettered nuclei listed below. Each lettered option may be selected once, more than once, or not at all.
1. Facial nerve a.) Superior salivatory nucleus
2. Oculomotor nerve b.) Edinger-Westphal nucleus
3. Glossopharyngeal nerve c.) Lacrimatory nucleus
4. Hypoglossal nerve d.) None of the above
1. Facial nerve - lacrimatory nucleus
2. Oculomotor nerve - Edinger-Westphal nucleus
3. Glossopharyngeal nerve - none of the above; inferior salivatory nucleus
4. Hypoglossal nerve - none of the above; muscles of the tongue
Match the numbered areas of referred pain with the appropriate lettered viscus originating the pain listed below. Each lettered option may be selected once, more than once, or not at all.
a.) Heart
b.) Appendix
c.) Gallbladder
d.) Stomach
e.) None of the above
1 (epigastrium)- stomach
2 (tip of the right shoulder)- gallbladder
3 (medial part of the left upper arm) - heart
4 (umbilicus) - appendix
The dura mater of the brain is conventionally described as two layers: the endosteal layer and the meningeal layer. These are closely united except along certain lines, where they separate to form venous sinuses.
B) Both statements are true.
Which of the following is not true about the endosteal layer of the dura mater?
C) At the foramen magnum, it becomes continuous with the dura mater of the spinal cord.
At the foramen magnum, it does not become continuous with the dura mater of the spinal cord.
Which of the following is not true about the meningeal layer of the dura mater?
D) Outside the skull, the sheaths fuse with the perineurium of the nerves.
Outside the skull, the sheaths fuse with the epineurium of the nerves.
True or False: The endosteal and meningeal layers of the dura mater are both considered as dura mater proper.
False
Only the meningeal layer is the dura mater proper.
True or False: Falx cerebri is a sickle-shaped fold of arachnoid mater that lies in midline between the two cerebral hemispheres.
False
Falx cerebri is a sickle-shaped fold of dura mater that lies in midline between the two cerebral hemispheres.
True or False: Tentorium cerebelli is a crescent-shaped fold of dura mater that roofs over the middle cranial fossa.
False
Tentorium cerebelli is a crescent-shaped fold of dura mater that roofs over the posterior cranial fossa.
The tentorium cerebelli is a small, sickle-shaped fold of dura mater attached to the internal occipital crest, which projects forward between the two cerebellar hemispheres. Meanwhile, the diaphragmatic sellae is a small circular fold of dura mater that forms the roof for the sella turcica.
A) Only the second statement is true.
The falx cerebelli is a small, sickle-shaped fold of dura mater attached to the internal occipital crest, which projects forward between the two cerebellar hemispheres.
A small opening in the center of the diaphragma sellae allows the passage of the stalk of the
B) Hypophysis cerebri
Hypophysis cerebri is another name for pituitary gland.
Stimulation of the dural sensory endings above the level of the tentorium cerebelli produces referred pain to an area of skin on the same side of the head. Meanwhile, stimualtion of the dural endings below the level of the tentorium cerebelli produces referred pain to the back of the scalp and neck along the distribution of the lesser occipital nerve.
C) Only the first statement is true.
Meanwhile, stimualtion of the dural endings below the level of the tentorium cerebelli produces referred pain to the back of the scalp and neck along the distribution of the greater occipital nerve.
From the clinical standpoint, what is the most important artery supplying the dura mater?
B) Middle meningeal
Numerous arteries supply the dura mater and they include: the internal carotid, maxillary, ascending pharyngeal, occipital, and vertebral arteries. From the clinical standpoint, the most important is the middle meningeal artery, which can be damaged in head injuries.
Which of the following is not true about the middle meningeal artery?
D) It enters the cranial cavity through the foramen lacerum.
It enters the cranial cavity through the foramen spinosum.
The anterior branch of the middle meningeal artery deeply grooves or tunnels the anterior-inferior angle of the parietal bone. The course of this branch corresponds roughly to the line of the underlying precentral gyrus of the brain.
C) Only the first statement is true.
The course of this branch corresponds roughly to the line of the underlying postcentral gyrus of the brain.
True or False: The venous sinuses of the cranial cavity are situated outside the dura mater.
False
The venous sinuses of the cranial cavity are situated between the layers of the dura mater.
The blood in the dural sinuses ultimately drains into the _________.
D) Internal jugular vein
All of the following are characteristics of the dural venous sinuses, except:
C) None of these
True or False: Emissary veins are valveless veins that connect the dural venous sinuses with the diploic veins of the skull and with the veins of the scalp.
True
Which of the following is not true about the arachnoid matter?
A) It is separated from the dura by the subdural space, which is filled with cerebrospinal fluid.
It is separated from the dura by the subdural space, which is filled by a thin film of fluid.
Arachnoid villi serve as sites where the cerebrospinal fluid diffuses into the bloodstream. They are most numerous along the inferior sagittal sinus.
C) Only the first statement is true.
They are most numerous along the superior sagittal sinus.
All the cerebral arteries and veins lie in the __________ space, as do the cranial nerves.
A) Subarachnoid
The arachnoid mater forms a sheath for the optic nerve, which extends into the orbital cavity through the optic canal and fuses with the sclera of the eyeball. Thus, the subarachnoid space extends around the optic nerve as far as the eyeball.
A) Both statements are true.
Usually, the arachnoid mater fuses with the epineurium of the nerves at their point of exit from the skull.
The cerebrospinal fluid is produced by the arachnoid granulations within the lateral, third, and fourth ventricles of the brain. This fluid escapes from the ventricular system of the brain through the three foramina in the floor of the fourth ventricle and so enters the subarachnoid space.
B) Both statements are false.
The cerebrospinal fluid is produced by the choroid plexuses within the lateral, third, and fourth ventricles of the brain. This fluid escapes from the ventricular system of the brain through the three foramina in the roof the fourth ventricle and so enters the subarachnoid space.
The spinal subarachnoid space extends down as far as the lower border of the:
C) Second sacral vertebra
Which of the following is incorrect about the pia mater?
C) The cerebral veins entering the substance of the brain carry a sheath of pia with them
The cerebral arteries entering the substance of the brain carry a sheath of pia with them.
True or False: The dura mater is a dense, strong, fibrous membrane that encloses the spinal cord, but not the cauda equina.
False
The dura mater is a dense, strong, fibrous membrane that encloses the spinal cord and the cauda equina.
The dura covering the spinal cord is continuous above through the foramen magnum with the endosteal layer of the dura covering the brain. Inferiorly, the dura ends on the conus medullaris at the level of the lower border of the second sacral vertebra.
B) Both statements are false.
The dura covering the spinal cord is continuous above through the foramen magnum with the meningeal layer of the dura covering the brain. Inferiorly, the dura ends on the filum terminale at the level of the lower border of the second sacral vertebra.
True or False: The arachnoid mater continues along the spinal nerves, forming small lateral extensions of the subdural space.
False
The arachnoid mater continues along the spinal nerves, forming small lateral extensions of the subarachnoid space.
From which meninx is the ligamentum denticulatum formed?
B) Pia matter
The pia mater, a vascular membrane that closely covers the spinal cord, is thickened on either side between the nerve roots to form the ligamentum denticulatum, which passes laterally to adhere to the arachnoid and dura.
The falx cerebri is a vertical sheet of dura between the cerebral hemispheres. Meanwhile, the falx cerebelli is a horizontal sheet that projects forward between the cerebrum and cerebellum.
A) Only the first statement is true.
The tentorium cerebelli is a horizontal sheet that projects forward between the cerebrum and cerebellum. Both the falx cerebri and tentorium cerebelli limit the excessive movements of the brain within the skull.
Which of the following is a characteristic of the arachnoid mater?
C) All of these
In lateral movements of the head, the lateral surface of one hemisphere hits the side of the skull. Meanwhile, the medial surface of the opposite hemisphere hits the side of the falx cerebri.
A) Both statements are true.
Which of the following will not likely to occur with superior movement of the head?
C) The superior surface of the cerebellum presses against the inferior surface of the falx cerebelli.
The superior surface of the cerebellum presses against the inferior surface of the tentorium cerebelli.
When the brain moves relative to the skull and the dural septa, which of the following structures is least likely to be injured?
D) Arteries
The tortuous arteries, with their strong walls, are rarely damaged.
True or False: The most common artery to be damaged in epidural hemorrhage is the posterior division of the middle meningeal artery.
False
The most common artery to be damaged in epidural hemorrhage is the anterior division of the middle meningeal artery.
Subdural hemorrhage results from tearing of the superior cerebral veins at their point of entrance into the superior sagittal sinus. The cause is usually a blow on the front or the back of the head, causing excessive anteroposterior displacement of the brain.
C) Both statements are true.
Which of the following is not true about the epidural hemorrhage?
A) None of these
In patients with subdural hematoma, the blood accumulates in the space between the meningeal layer of the dura and the arachnoid, producing a long crescent-shaped hyperdense rim of blood that extends from anterior to posterior. With large hematoma, the brain sulci are obliterated, and the midline structures are displaced to the opposite side.
B) Both statements are true.
True or False: The dura mater receives its sensory nerve supply from the trigeminal and the first three cervical nerves.
True
The dura above the tentorium is innervated by the trigeminal nerve, and the headache is referred to the forehead and face. The dura below the tentorium is innervated by the cervical nerves, and the headache is referred to the back of the head and neck
True or False: A tumor above the tentorium tends to produce a headache referred to the front of the head, while a tumor below the tentorium produces a headache referred to the back of the head.
True
Which of the following is not true about migraine?
C) The headache is due to constriction of the cerebral arteries and branches of external carotid artery.
The headache is due to dilatation and stretching of the cerebral arteries and branches of external carotid artery. Therefore, both the arteries inside and outside the skull can be affected.
True or False: The large-diameter cranial nerves of long length are particularly prone to damage during head injuries.
False
The small-diameter cranial nerves of long length are particularly prone to damage during head injuries.
Meningiomas arise from the arachnoid villi found along the dural venous sinuses. They are therefore most commonly found along the inferior sagittal sinus and the sphenoparietal sinuses.
C) Only the first statement is true.
They are therefore most commonly found along the superior sagittal sinus and the sphenoparietal sinuses.
True or False: The optic nerves are surrounded by sheaths derived from the pia mater, arachnoid mater, and dura mater.
True
During descent of the fetal head through the birth canal during labor, the bones of the calvarium overlap, a process known as molding. If this process is excessive or takes place too rapidly, an abnormal strain is put on the tentorium cerebelli.
A) Only the first statement is true.
If this process is excessive or takes place too rapidly, an abnormal strain is put on the falx cerebri.
The following statements concern the meninges of the brain:
B) The cranial venous sinuses run between the meningeal and endosteal layers of dura mater.
The periosteal (endosteal) layer of dura mater is continuous with the sutural ligaments of the skull. It is also continuous through the foramen magnum with the periosteum outside the skull.
As each cranial nerve passes through the foramen in the skull, it is surrounded by a tubular sheath of pia, arachnoid, and dura mater.
The meninges extend anteriorly through the optic canal and fuse with the sclera of the eyeball.
The following general statements concern the meninges:
D) The cerebrospinal fluid in the arachnoid villi is able to drain into the venous sinuses through small tubules lined with endothelial cells.
The cisterna cerebellomedullaris lies between the inferior surface of the cerebellum and the roof of the fourth ventricle and contains cerebrospinal fluid.
The arachnoid mater is not permeable to cerebrospinal fluid.
The extradural space that separates the dural sheath of the spinal cord and the walls of the vertebral canal contains the internal vertebral venous plexus.
The following statements concern the tentorium cerebelli:
B) It is formed from the meningeal layer of the dura mater.
The free border is attached anteriorly to the anterior clinoid processes of the sphenoid bone.
The sigmoid sinus does not lie within the free border of the tentorium cerebelli.
In the anterior edge, there is the tentorial notch.
The tentorium cerebelli separates the cerebellum from the occipital lobes.
The following statements concern headache:
C) Brain tissue is insensitive to pain.
Intracranial pain arises from receptors situated in the dura mater.
An expanding cerebral tumor located in the posterior cranial fossa would produce pain referred to the back of the neck.
Headaches associated with presbyopia are due to tonic spasm of the ciliary muscles of the eyes.
The following statements concern the subarachnoid space:
B) The cerebral arteries and veins are located in the subarachnoid space.
It extends inferiorly as far as the second sacral vertebra.
The cranial nerves lie inside the subarachnoid space.
The arachnoid villi project into the venous sinuses as minute outpouchings of the subarachnoid space.
The following statements concern the cavernous sinus:
D) It is related medially to the pituitary gland and the sphenoid air sinus.
It has the internal carotid artery passing through it.
It has the oculomotor, trochlear, and ophthalmic division of the trigeminal nerve in its lateral wall.
It drains directly posteriorly into the superior and inferior petrosal sinuses.
It communicates anteriorly via the superior ophthalmic vein with the facial vein.
The following structure limits the rotatory movements of the brain within the skull:
B) Falx cerebri
The following nerves are sensory to the dura mater:
B) Trigeminal nerve
Which of the following is not true about the ventricular system?
C) The two lateral ventricles communicate through the foramen of Magendie with the third ventricle.
The two lateral ventricles communicate through the foramen of Monro (interventricular foramen) with the third ventricle.
True or False: The ventricles are developmentally derived from the cavity of the neural tube.
True
Which of the following is not true about the interventricular foramen?
D) None of these
The interventricular foramen is also known as the foramen of Monro.
True or False: The hippocampus is composed of white matter, however, its ventricular surface is covered by a thin layer of gray matter called the alveus.
False
The hippocampus is composed of gray matter, however, its ventricular surface is covered by a thin layer of white matter called the alveus, which is formed from the axons of the cells of the hippocampus.
True or False: The blood supply of the choroid plexuses of the third and lateral ventricles is derived from the choroidal branches of the internal carotid and basilar arteries.
True
The blood supply of the choroid plexus of the fourth ventricle is derived from the posterior inferior cerebellar arteries.
Which of the following is not true about the cerebral aqueduct?
B) None of these
Which of the following is not true about the fourth ventricle?
A) None of these
True or False: The cavity of the fourth ventricle communicates with the subarachnoid space through a single median opening and two lateral apertures situated on its roof.
True
The median opening is called foramen of Magendie, while the lateral apertures are called foramina of Luschka.
Which of the following is not true about the central canal?
B) It has a choroid plexus.
It has no choroid plexus.
True or False: The subarachnoid space completely surrounds the brain and extends along the olfactory nerves to the mucoperiosteum of the nose.
True
True or False: The subarachnoid space extends along the cerebral blood vessels as they enter and leave the substance of the brain and stops where the vessels become a capillary.
False
The subarachnoid space stops where the blood vessels become an arteriole or a venule.
Around the base of the brain, the arachnoid mater does not closely follow the surface of the brain. In such a case, the subarachnoid space expands to form subarachnoid cisterns. All of the following are one of the largest cisterns, except:
A) None of these
True or False: The subarachnoid space extends beyond the lower end of the spinal cord and invests the cauda equina.
True
The subarachnoid space ends below at the level of the interval between the second and the third sacral vertebrae.
The subarachnoid space surrounds the cranial and spinal nerves and follows them to the point where they leave the skull and vertebral canal. Here, the pia mater fuses with the perineurium of each nerve.
B) Only the first statement is true.
Here, the arachnoid mater and pia mater fuse with the perineurium of each nerve.
Which of the following is not true about the cerebrospinal fluid?
B) Only a few cells are present, and these are the monocytes.
Only a few cells are present, and these are lymphocytes. The normal lymphocyte count is 0 to 3 cells per cubic millimeter.
In lateral recumbent position, the cerebrospinal fluid pressure, as measured by spinal tap, is about 60 to 150 mm Hg. This pressure may be raised by straining, coughing, or compressing the external jugular veins in the neck.
B) Both statements are false.
In lateral recumbent position, the cerebrospinal fluid pressure, as measured by spinal tap, is about 60 to 150 mm of water. This pressure may be raised by straining, coughing, or compressing the internal jugular veins in the neck.
All of the following are characteristics of the cerebrospinal fluid, except:
C) Pressure: 60-150 mm Hg
It should be pressure: 60-150 mm of water.
All of the following are funtions of the cerebrospinal fluid, except:
C) It cushions and protects the central and peripheral nervous systems from trauma.
It cushions and protects the central nervous system from trauma.
The choroid plexuses actively secrete cerebrospinal fluid, creating a large pressure gradient. At the same time, they actively transport nervous system metabolites from the cerebrospinal fluid into the blood.
C) Only the second statement is true.
The choroid plexuses actively secrete cerebrospinal fluid, creating a small pressure gradient. Active transport explains the fact that the concentrations of potassium, calcium, magnesium, bicarbonate, and glucose are lower in the cerebrospinal fluid than in the blood plasma.
True or False: The production of cerebrospinal fluid is pressure regulated.
False
The production of cerebrospinal fluid is not pressure regulated (as in the case of blood pressure), and it continues to be produced even if the reabsorption mechanisms are obstructed.
The circulation of the cerebrospinal fluid is aided by the:
A) Both of these
Some of the cerebrospinal fluid moves inferiorly in the subarachnoid space around the spinal cord and cauda equina. Here, the fluid is at a dead end, and its further circulation relies on the pulsations of the spinal arteries and the movements of the vertebral column, respiration, coughing, and the changing of the positions of the body.
C) Both statements are true.
True or False: The cerebrospinal fluid only bathes the ependymal and pial surfaces of the brain and spinal cord.
False
The cerebrospinal fluid not only bathes the ependymal and pial surfaces of the brain and spinal cord but also penetrates the nervous tissue along the blood vessels.
True or False: Each arachnoid villus is a diverticulum of the subarachnoid space that pierces the arachnoid mater.
False
Each arachnoid villus is a diverticulum of the subarachnoid space that pierces the dura mater.
True or False: The arachnoid granulations decrease in number and size with age and tend to become calcified with advanced age.
False
The arachnoid granulations increase in number and size with age.
True or False: The absorption of cerebrospinal fluid into the venous sinuses occurs when the cerebrospinal fluid pressure exceeds the venous pressure in the sinus.
True
Should the venous pressure rise and exceed the cerebrospinal fluid pressure, compression of the tips of the arachnoid villi closes the tubules and prevents reflux of blood into the subarachnoid space. The arachnoid villi this serve as valves.
True or False: The rate of production of cerebrospinal fluid controls the cerebrospinal fluid pressure.
False
Because the rate of production of cerebrospinal fluid from the choroid plexuses is constant, the rate of absorption of cerebrospinal fluid through the arachnoid villi controls the cerebrospinal fluid pressure.
Which of the following is not true about the blood-brain barrier?
B) Its permeability is directly related to the size of the molecules and their lipid solubility.
Its permeability is inversely related to the size of the molecules directly related to their lipid solubility.
True or False: In molecular terms, the blood-brain barrier is a continuous lipid bilayer that encircles the endothelial cells and isolates the brain tissue from the blood.
False
This explains how lipophilic molecules can readily diffuse through the barrier, whereas hydrophilic molecules are excluded.
True or False: The blood-brain barrier does not exist in the newborn.
False
The blood-brain barrier exists in the newborn, but is it more permeable to certain substances than it is in the adult.
True or False: The structure of the blood-brain barrier is identical in all regions of the central nervous system.
False
The structure of the blood-brain barrier is not identical in all regions of the central nervous system. In those areas where the blood-brain barrier appears to be absent, the capillary endothelium contains fenestrations across which proteins and small organic molecules may pass from the blood to the nervous tissue.
Site/s which neuronal receptors may sample the content of the plasma directly
C) Hypothalamus
The area postrema of the floor of the fourth ventricle and the hypothalamus may serve as sites at which neuronal receptors may sample the content of the plasma directly.
True or False: A barrier similar to the blood-brain barrier exists in the choroid plexuses.
True
As a result, there is free passage of water, gases, and lipid-soluble substances from the blood to the cerebrospinal fluid. Macromolecules such as proteins and most hexoses other than glucose are unable to enter the cerebrospinal fluid.
True or False: There is no physiologic barrier between the cerebrospinal fluid and the extracellular compartment of the central nervous system.
True
True or False: The extracellular spaces of the nervous tissue are in almost direct continuity with the subarachnoid space.
True
There are no intercellular junctions between adjacent pial cells or between adjacent astrocytes.
Which of the following is not true about papilledema?
A) A rise of cerebrospinal fluid pressure caused by an intracranial tumor will compress the thin walls of the retinal artery as it crosses the extension of the subarachnoid space to enter the optic nerve.
A rise of cerebrospinal fluid pressure caused by an intracranial tumor will compress the thin walls of the retinal vein as it crosses the extension of the subarachnoid space to enter the optic nerve.
It All of the following factors may cause hydrocephalus, except:
C) Abnormal decrease in the formation of the cerebrospinal fluid
It should be abnormal increase in the formation of the cerebrospinal fluid.
True or False: Hydrocephalus can occur even with a normal cerebrospinal fluid pressure.
True
In these rare cases, there is a compensatory hypoplasia or atrophy of the brain substance.
True or False: In communicating hydrocephalus, the raised pressure of the cerebrospinal fluid is due to blockage at some point between its formation at the choroid plexuses and its exit through the foramina in the roof of the fourth ventricle.
False
In noncommunicating hydrocephalus, the raised pressure of the cerebrospinal fluid is due to blockage at some point between its formation at the choroid plexuses and its exit through the foramina in the roof of the fourth ventricle. In communicating hydrocephalus, there is no obstruction within or to the outflow from the ventricular system.
True or False: An obstruction in the cerebral aqueduct causes as symmetrical distention of both lateral ventricles and of the third ventricle.
True
An obstruction in the cerebral aqueduct may be congenital or may result from inflammation or pressure from a tumor.
True or False: Obstruction of the foramen of Monro causes symmetrical dilatation of both lateral ventricles and the third and fourth ventricles.
False
Obstruction of the median aperture (foramen of Magendie) in the roof of the fourth ventricle and the two lateral apertures (foramen of Luschka) in the lateral recesses of the fourth ventricle causes symmetrical dilatation of both lateral ventricles and the third and fourth ventricles.
All of the following causes diminished absorption of the cerebrospinal fluid, except?
B) Obstruction of external jugular vein
Intracranial pneumography is the replacement of cerebrospinal fluid within the ventricles and subarachnoid space with air or oxygen. Because the air or oxygen is more dense than the fluid or neural tissue, the ventricles and cerebral gyri can be visualized.
D) Only the first statement is true.
Because the air or oxygen is less dense than the fluid or neural tissue, the ventricles and cerebral gyri can be visualized.
Normally, the cerebrospinal fluid is clear and colorless. Which of the following abnormal findings below is incorrect?
B) An decrease in gamma globulins is seen multiple sclerosis.
In multiple sclerosis, the gamma globulin is elevated due to production of immunoglobulins in the brain and spinal cord.
A normal cerebrospinal fluid does not contain red blood cells. Which of the following abnormal findings below is not true?
C) Gross blood in the cerebrospinal fluid is usually caused by contamination brought about by puncture of a vertebral artery by the spinal tap needle.
Gross blood in the cerebrospinal fluid is usually caused by contamination brought about by puncture of a vertebral vein by the spinal tap needle.
True or False: The glucose level in the cerebrospinal fluid may disappear completely in acute viral meningitis but remains normal in bacterial infections.
False
The glucose level in the cerebrospinal fluid may disappear completely in acute bacterial meningitis but remains normal in viral infections.
True or False: Should the tumor completely occupy the vertebral canal in the region of the cauda equina, no cerebrospinal fluid may flow out of the spinal tap needle.
True
True or False: In the presence of a tumor, the cerebrospinal fluid may become yellow and clot simultaneously.
True
In the presence of a tumor, the cerebrospinal fluid may become yellow and clot simultaneously, owing to the rise in protein content.
True or False: Toxic substances such as bilirubin can readily enter the central nervous system and produce yellow of the brain and kernicterus in adults.
False
In the fetus, newborn child, or premature infant, the blood-brain barrier is not fully developed. Toxic substances such as bilirubin can readily enter the central nervous system and produce yellowing of the brain and kernicterus. This is not possible in the adult.
The systemic administration of penicillin results in large amounts of the drug entering the central nervous system. This is unfortunate because penicillin in high concentrations is toxic to nervous tissue.
A) Both statements are false.
The systemic administration of penicillin results in only a small amount of the drug entering the central nervous system. This is fortunate because penicillin in high concentrations is toxic to nervous tissue. In the presence of meningitis, however, the meninges become more permeable locally, at the site of inflammation, thus permitting sufficient antibiotic to reach the infection.
All of the following drugs can readily cross the blood-brain barrier, except:
C) Phenylbutazone
Phenylbutazone is a drug that becomes bound to plasma protein, and the large drug protein molecule is unable to cross the blood-brain barrier.
In Parkinson disease, there is a deficiency of the neurotransmitter dopamine in the corpus striatum. Unfortunately, dopamine cannot be used in the treatment, as it will not cross the blood-brain barrier.
D) Both statements are true.
L-Dopa readily crosses the barrier and has been used with great success.
True or False: Brain tumors frequently possess blood vessels that have no blood-brain barriers; however, slow grow tumors often have normal vascular barriers.
True
Anaplastic malignant astrocytomas, glioblastomas, and secondary metastatic tumors lack the normal vascular barriers.
A 55-year old man was being investigated for signs and symptoms that suggested the presence of a cerebral tumor. Examination of the CT scan showed gross enlargement and distortion of the left lateral ventricle. What is the most likely location of the tumor in this patient?
A) Left foramen of Monro
Since the left lateral ventricle was the only part of the ventricular system that showed distention and distortion, one can assume that the tumor had closed off the left interventricular foramen, and therefore, was in the vicinity of that foramen.
A 3-year old child had been referred to the children's hospital because the circumference of his head greatly exceeded the normal limit for his age. After a careful history had been taken and a detailed physical examination had been performed, a diagnosis of hydrocephalus was made? All of the following are common causes of hydrocephalus in young children, except?
A) None of these
Blockage of the arachnoid granulations may be due to subarachnoid bleeding or inflammatory exudate.
A man was operated on and was found to have a large astrocytoma of the vermis of the cerebellum. Which of the following signs and symptoms is not consistent with this diagnosis?
A) Peripheral deafness on the right side is due to involvement of the right eighth cranial nerve by the tumor mass.
Central deafness on the right side is due to involvement of the right eighth cranial nerve by the tumor mass. There may also be loss of the muscles of the right limbs as the tumor spreads to involve the right cerebellar hemisphere.
A 4-year old girl was found to have tuberculous meningitis. She was immediately admitted to the hospital, and administration of streptomycin and isoniazid was commenced. As soon as the therapy was started, she was also administered steroid hormones to reduce the incidence of adhesions. All of the following statements below explain the importance of preventing the formation of adhesion in the subarachnoid space, except:
A) Adhesions can block the openings in the floor of the fourth ventricle, thus preventing the escape of the cerebrospinal fluid into the subarachnoid space from within the ventricular system.
Adhesions can block the openings in the roof of the fourth ventricle, thus preventing the escape of the cerebrospinal fluid into the subarachnoid space from within the ventricular system. Thus, adhesion of the meninges may result in hydrocephalus.
A 5-year old girl with symptoms of headache, general malaise, and vomiting was admitted to the children's hospital. On examination, the body temperature was found to be 104°F, and the pulse rate was rapid. Attempts to flex the neck produced pain and resulted in patient flexing her hip and knee joints. A spinal tap was performed; the cerebrospinal fluid was seen to be cloudy, and the pressure was raised to 190 mm of water. Microscopic examination of the fluid showed a large number of polymorphonuclear leukocytes. A diagnosis of meningitis was made. Subsequent culture revealed the infection to be a meningococcal meningitis. How does the presence of blood-brain barrier influence the choice and dose of antibiotics to be used in this patient?
A) Penicillin should not be used because when this antiobiotic is injected intramuscularly, it is found in much lower concentrations in the cerebrospinal fluid than in the blood.
Penicillin, when injected intramuscularly into a normal individual, is found in much lower concentrations in the cerebrospinal fluid than in the blood due to the presence of blood-brain barrier.
The following are parts of the brain where the capillary endothelium contains open fenestrations across which proteins and small organic molecules may pass and where the blood-brain barrier appears to be absent, except:
B) Anterior lobe of pituitary gland
These areas include the pineal gland, the posterior lobe of the pituitary gland ,the tuber cinereum ,the wall of the optic recess, and the vascular area postrema at the inferior end of the fourth ventricle.
True or False: There is absence of the blood-barrier in the region of the hypothalamus.
True
The absence of the blood-brain barrier in the region of the hypothalamus may allow this area of the brain to sample the chemical content of the plasma, so appropriate modifications of metabolic activity may take place, thus protecting the nervous tissue as a whole
The following statements concern the ventricular system:
D) The cerebral aqueduct connects the third ventricle with the fourth ventricle.
The two lateral ventricles do not communicate directly with one another through the foramen of Monro.
The ventricles are developed from the neural tubein the embryo.
It is lined throughout with ependyma, which is a single layer of cuboidal or columnar cells.
The choroid plexuses are found in the lateral ventricles and the third and the fourth ventricles.
The following statements concern the ventricular system:
C) The choroid plexus of the lateral ventricle projects into the cavity on its medial side through the choroidal fissure.
The pineal gland is not suspended from the roof of the fourth ventricle.
The nerve centers controlling the heart rate and blood pressure lie beneath the floor of the fourth ventricle.
The foramen of Magendie is an aperture in the roof of the fourth ventricle.
The fourth ventricle has a diamond-shaped floor called the rhomboid fossa.
The following statements concern the blood-brain barrier:
D) The endothelial cells of the blood capillaries are nonfenestrated.
It protects the brain from toxic compounds of high molecular weight.
The endothelial cells of the blood capillaries are not held together by localized tight junctions.
It is not present in the pineal gland.
The following statements concern the blood-brain barrier:
B) In the newborn child, the blood-brain barrier is not fully developed.
Chloramphenicol and tetracyclines can cross the barrier.
Cerebral trauma or inflammation may have great effect on the integrity of the blood-brain barrier.
Gases and water pass readily through the barrier, whereas glucose and electrolytes pass slowly.
The following statements concern the blood-cerebrospinal fluid barrier:
D) The belt-like tight junctions between the choroidal ependymal cells form the barrier.
The proteins and most hexoses, other than glucose, are unable to cross the barrier.
Gases, water, and other lipid soluble substances readily pass through the barrier.
The basement membrane of the endothelial cells plays no part in the formation of the barrier.
The following structures are associated with the roof of the fourth ventricle:
D) Choroid plexus
The choroid plexus is present in the roof of the fourth ventricle.
The following statements concern the cerebrospinal fluid in the fourth ventricle:
A) It escapes the subarachnoid space through the apertures in the roof the fourth ventricle.
It is produced mainly by the choroid plexuses of the lateral, third, and fourth ventricles.
C) It leaves the midbrain through the cerebral aqueduct.
D) It enters the spinal cord through the central canal.
The lateral boundaries of the fourth ventricle are formed by:
C) Cerebellar peduncles
The following important nuclei lie beneath the floor of the fourth ventricle:
D) Hypoglossal nucleus
The following statements concern the third ventricle:
B) It is situated between the thalami.
It communicates with the lateral ventricles through the interventricular foramen.
It is continuous with the fourth ventricle through the cerebral aqueduct.
The choroid plexus is located in the roof and receives its arterial supply through the internal carotid and basilar arteries.
The following statements concern the subarachnoid space:
D) It is the interval between the arachnoid mater and the pia mater and it communicates with the cisterns.
It contains cerebrospinal fluid, the cerebral arteries, and the cerebral veins.
The fourth ventricle drains into it through three openings in its roof.
The space surrounds the cranial and spinal nerves where they leave the skull and the vertebral canal.
The following statements concern the formation of the cerebrospinal fluid:
B) Some of the fluid originates from the brain substance.
It is largely formed by the choroid plexuses and it is actively secreted by the ependymal cells covering the choroid plexuses.
The fluid is produced continuously at a rate of about 0.5 mL per minute.
The brain and spinal cord have no lymphatic vessels.
The following statements concern the cerebrospinal fluid:
A) The cerebrospinal fluid pressure in the subarachnoid space rises if the internal jugular veins in the neck are compressed.
It extends inferiorly in the subarachnoid space to the level of the lower border of the second sacral vertebra.
It exits from the ventricular system through the foramina of Luschka and Magendie.
Its circulation in the subarachnoid space is aided by the pulsations of the cerebral and spinal arteries.
The following statements concern the absorption of the cerebrospinal fluid:
A) The arachnoid villi play an important role in the absorption of cerebrospinal fluid into the cranial venous sinuses.
The fluid does not pass into the blood by active transport through the cells forming the arachnoid villi.
The minor sites for the absorption of the cerebrospinal fluid are into the veins in the subarachnoid space and the perineural lymph vessels.
The fine tubules found within the arachnoid villi play a major role in the flow of the cerebrospinal fluid into the venous sinuses.
A 24-year old woman complaining of recent onset of severe headaches and several attacks of morning vomiting was seen by a neurologist. A thorough physical examination revealed findings suggesting that she might have an intracranial tumor involving the cerebellum. The physician ordered an MRI of the patient's brain with particular reference to the contents of the posterior cranial fossa. Figure 16-25 is a coronal MRI (contrast enhanced) through the fourth ventricle. radiologist made the following correct observations in his report except:
C) The cavity of the fourth ventricle was distorted and larger than normal.
The size and the shape of the cavity of the fourth ventricle were within normal limits.
A 21-year-old pregnant woman was invited to a reunion party, and during the course of the evening, she drank several gin and tonics. The party was followed by several others extending over a 3-week period during which she drank heavily. Six months later, she gave birth to a boy who was diagnosed as having congenital hydrocephalus. The pediatric neurologist carefully questioned the mother and came to the following correct conclusions, except:
A) The consumption of a large amount of alcohol during pregnancy usually has no adverse effects on the developing fetus.
Many chemical substances when consumed are toxic to the central nervous system, and alcohol in large quantities is one of the worst offenders. During the first trimester, alcohol can readily access the brain at a time when it is particularly vulnerable. Before a physician prescribes a therapeutic drug, he or she must know whether the drug will cross the blood-brain barrier and what effect, if any, that drug will have on the central nervous system.
The brain is supplied by the two internal carotid arteries and one vertebral artery. The three arteries lie within the subarachnoid space, and their branches anastomose on the inferior surface of the brain to form the circle of Willis.
C) Both statements are false.
The brain is supplied by the two internal carotid and two vertebral arteries. The four arteries lie within the subarachnoid space, and their branches anastomose on the inferior surface of the brain to form the circle of Willis.
The ophthalmic artery supplies the following structures, except:
B) None of these
The ophthalmic artery also supplies the eye and other orbital structures.
True or False: The posterior communicating artery runs posteriorly above the trochlear nerve to join the posterior cerebral artery.
False
The posterior communicating artery runs posteriorly above the oculomotor nerve to join the posterior cerebral artery.
Which of the following is not true about the anterior cerebral artery?
D) It is the larger terminal branch of the internal carotid artery.
It is the smaller terminal branch of the internal carotid artery.
Which of the following is not true about the middle cerebral artery?
B) Its cortical branches supply the entire lateral surface of the hemisphere.
Its cortical branches supply the entire lateral surface of the hemisphere, except for the narrow strip supplied by the anterior cerebral artery, as well as the occipital pole and the inferolateral surface of the hemisphere, which are supplied by the posterior cerebral artery.
What are the five cerebral branches of the internal carotid artery?
OAMPoC
Ophthalmic artery
Anterior cerebral artery
Middle cerebral artery
Posterior communicating artery
Choroidal artery
The vertebral artery ascends the neck by passing through the foramina in the transverse processes of the seven cervical vertebrae. It enters the skull through the foramen magnum and pierces the dura mater and arachnoid mater to enter the subarachnoid space.
C) Only the second statement is true.
The vertebral artery ascends the neck by passing through the foramina in the transverse processes of the upper six cervical vertebrae.
At the ______, the vertebral artery joins the vessel of the opposite side to form the basilar artery.
C) lower border of the pons
What are the five branches of the cranial portion of the vertebral artery?
Men PAMP
Meningeal arteries
Posterior spinal arteries
Anterior spinal artery
Medullary arteries
Posterior inferior cerebellar artery
Which of the following is not true about the branches of the cranial portion of the vertebral artery?
D) The anterior spinal artery may arise from the vertebral artery or the posterior inferior cerebellar artery.
The posterior spinal artery may arise from the vertebral artery or the posterior inferior cerebellar artery.
All of the following structures are supplied by the posterior inferior cerebellar artery, except:
B) Choroid plexus of the third ventricle
It should be choroid plexus of the fourth ventricle. Posterior inferior cerebellar artery also supplies the undersurface of the cerebellar hemispheres.
Which of the following is not true about the basilar artery?
C) It ascends in a groove on the posterior surface of the pons.
It ascends in a groove on the anterior surface of the pons.
What are the five branches of the basilar artery?
APonLaSPo
Anterior inferior cerebellar artery
Pontine arteries
Labyrinthine artery
Superior cerebellar artery
Posterior cerebral artery
The labyrinthine artery is a long, narrow artery that accompanies the facial and the vestibulocochlear nerves into the internal acoustic meatus and supplies the internal ear. It often arises as a branch of the superior cerebellar artery.
A) Only the first statement is true.
It often arises as a branch of the anterior inferior cerebellar artery.
All of the following structures are supplied by the superior cerebellar artery, except:
A) Pituitary gland
Superior cerebellar artery also supplies the superior surface of the cerebellum.
Which of the following is not true about the posterior cerebral artery?
A) Its cortical branches supply the superolateral and medial surfaces of the temporal lobe.
Its cortical branches supply the inferolateral and medial surfaces of the temporal lobe.
All of the following arteries contribute to the circle of Willis, except:
B) Middle cerebral artery
The anterior communicating, anterior cerebral, internal carotid, posterior communicating, posterior cerebral, and basilar arteries all contribute to the circle of Willis.
Which of the following is incorrect about the circle of Willis?
B) It is formed by the anastomosis between the two internal carotid arteries and the basilar artery.
It is formed by the anastomosis between the two internal carotid arteries and the two vertebral arteries.
The corpus striatum and the internal capsule are supplied mainly by the medial and lateral striate cortical branches of the middle cerebral artery. The central branches of the anterior cerebral artery supply the remainder of these structures.
A) Only the second statement is true.
The corpus striatum and the internal capsule are supplied mainly by the medial and lateral striate central branches of the middle cerebral artery.
All of the following arteries supply the thalamus, except:
D) Superior cerebellar
All of the following arteries supply the midbrain, except:
C) Posterior communicating
All of the following arteries supply the pons, except:
C) Posterior cerebral
All of the following arteries supply the medulla oblongata, except:
C) None of these
The medulla oblongata is supplied by the vertebral, anterior and posterior spinal, posterior inferior cerebellar, and basilar arteries.
All of the following arteries supply the cerebellum, except:
B) None of these
The cerebral arteries receive a rich supply of sympathetic postganglionic nerve fibers, which are derived from the superior cervical sympathetic ganglion. .Stimulation of these nerves causes vasoconstriction of the cerebral arteries.
D) Both statements are true.
However, under normal conditions, the local blood flow is mainly controlled by the concentrations of carbon dioxide, hydrogen ions, and oxygen present in the nervous tissue. A rise in the carbon dioxide and hydrogen ion concentrations and a lowering of the oxygen tension bring about a vasodilatation.
All of the following are characteristics of the veins of the brain, except:
C) They pierce and arachnoid mater and the endosteal layer of the dura mater.
They pierce and arachnoid mater and the meningeal layer of the dura mater.
Which of the following is not true about the external cerebral veins?
A) None of these
True or False: The capillary blood supply to the brain is greater in the gray matter than in the white matter.
True
This is to be expected, since the metabolic activity in the neuronal cell bodies in the gray matter is much greater than in the nerve processes in the white matter.
The blood supply to half of the brain is provided by the internal carotid and vertebral arteries on that side. Their respective streams come together in the posterior cerebral artery at a point where the pressure of the two is equal and they do not mix.
B) Only the first statement is true.
Their respective streams come together in the posterior communicating artery at a point where the pressure of the two is equal and they do not mix.
True or False: The two streams of blood from the two vertebral arteries can mix.
False
the two streams of blood from the vertebral arteries remain separate and on the same side of the lumen of the basilar artery and do not mix.
The most important factor in forcing the blood through the brain is the arterial blood pressure. This is opposed by the following factors, except:
A) Decreased blood viscosity
True or False: Cerebral blood flow remains remarkably constant despite changes in the general blood pressure.
True
This autoregulation of the circulation is accomplished by a compensatory lowering of the cerebral vascular resistance when the arterial pressure is decreased and a raising of the vascular resistance when the arterial pressure is increased.
Which of the following is not true about the posterior spinal arteries?
A) They supply the posterior two-thirds of the spinal cord.
They supply the posterior one-third of the spinal cord. The first three thoracic segments of the spinal cord are particularly vulnerable to ischemia should the segmental or radicular arteries in this region be occluded.
Which of the following is not true about the anterior spinal artery?
B) It may be extremely small in the cervical segments of the spinal cord.
It may be extremely small in the thoracic segments of the spinal cord. Should the segmental or radicular arteries be occluded in these regions, the fourth thoracic and the first lumbar segments of the spinal cord would be particularly liable to ischemic necrosis.
The great anterior medullary artery of Adamkiewicz, a large and important feeder artery, arises from the aorta in the lower thoracic or upper lumbar levels. It is unilateral and, in the majority of persons, enters the spinal cord from the right side.
B) Only the first statement is true.
It is unilateral and, in the majority of persons, enters the spinal cord from the left side.
True or False: The veins of the spinal cord drain mainly into the external vertebral venous plexus.
False
The veins of the spinal cord drain mainly into the internal vertebral venous plexus.
True or False: The vertebral arteries are the major supply of arterial blood to the brain.
False
The arterial blood reaches the brain through the two internal carotid and the two vertebral arteries; the internal carotid arteries are the major supply of arterial blood.
True or False: In the brain substance, further branching of the arteries occurs, but no further anastomoses take place.
True
It is the anastomoses on the brain surface that provide the vital collateral circulation should one of the arteries be occluded by disease.
True or False: If the occlusion of the anterior cerebral artery is distal to the anterior communicating artery, the collateral circulation is usually adequate to preserve the circulation.
False
If the occlusion of the anterior cerebral artery is proximal to the anterior communicating artery, the collateral circulation is usually adequate to preserve the circulation.
In anterior cerebral artery occlusion, contralateral hemiparesis and hemisensory loss involving mainly the leg and foot are due to the affectation of the paracentral lobule of cortex. Meanwhile, inability to identify objects correctly, apathy, and personality changes are due to the involvement of the frontal and temporal lobes.
C) Only the first statement is true.
Inability to identify objects correctly, apathy, and personality changes are due to the involvement of the frontal andparietal lobes.
All of the following are true about the manifestations of middle cerebral artery occlusion, except:
C) Contralateral homonymous hemianopia (damage to the optic tract)
It should be contralateral homonymous hemianopia (damage to the optic radiation).
All of the following are true about the manifestations of posterior cerebral artery occlusion, except:
B) None of these
Occlusion of the posterior cerebral artery may produce the following signs and symptoms:
1. Contralateral homonymous hemianopia with some degree of macular sparing due to damage to the calcarine cortex; macular sparing due to the occipital pole receiving collateral blood supply from the middle cerebral artery
2. Visual agnosia due to ischemia of the left occipital lobe
3. Impairment of memory due to possible damage to the medial aspect of the temporal lobe
True or False: In posterior cerebral artery occlusion, there is macular sparing because the occipital pole receives collateral blood supply from the posterior communicating artery.
False
In posterior cerebral artery occlusion, there is macular sparing because the occipital pole receives collateral blood supply from the middle cerebral arteries.
The signs and symptoms of internal carotid artery occlusion are similar to those of anterior cerebral artery occlusion. There is also partial or complete loss of sight on the contralateral side, but permanent loss is rare.
D) Both statements are false.
The signs and symptoms of internal carotid artery occlusion are similar to those of middle cerebral artery occlusion. There is also partial or complete loss of sight on the ipsilateralside, but permanent loss is rare.
True or False: Hyperventilation in anxiety states may reduce the cerebral blood flow.
True
Hyperventilation in anxiety states may reduce the cerebral blood flow by lowering the carbon dioxide content of the blood.
Which of the following is not true about the carotid sinus syndrome?
B) This occurs as the result of an increased number of nervous impulses passing up the sinus nerve, a branch of the vagus nerve, which connects with the cardioinhibitory and vasomotor centers.
This occurs as the result of an increased number of nervous impulses passing up the sinus nerve, a branch of the glossopharyngeal nerve, which connects with the cardioinhibitory and vasomotor centers.
Fat embolism usually follows severe fractures of one of the short bones. Fat globules from the macerated yellow marrow enter the nutrient veins, pass through the pulmonary circulation, and end up blocking multiple small cerebral end arteries.
A) Only the second statement is true.
Fat embolism usually follows severe fractures of one of the long bones.
Cerebral hemorrhage generally is due to rupture of an atheromatous artery and is most common in patients with hypotension. It usually occurs in individuals of middle age and often involves a rupture of the thin-walled lenticulostriate artery, a branch of the middle cerebral artery.
A) Only the second statement is true.
Cerebral hemorrhage generally is due to rupture of an atheromatous artery and is most common in patients with hypertension.
The anterior spinal artery supply the following parts of the spinal cord, except:
A) None of these
The anterior spinal artery also supply the anterior part of the lateral white columns.
All of the following are manifestations of anterior spinal artery occlusion, except:
D) Loss of position sense, vibration, and light touch
The following are manifestations of anterior spinal artery occlusion:
1. Loss of motor function (paraplegia) below the level of the lesion occurs due to bilateral damage to the corticospinal tracts
2. Bilateral thermoanesthesia and analgesia occur below the level of the lesion due to bilateral damage to the spinothalamic tracts
3. Weakness of the limb muscles due to damage of the anterior gray horns in the cervical or lumbar regions of the cord
4. Loss of bladder and bowel control occurs due to damage of the descending autonomic tracts
5. Intact position sense, vibration, and light touch due to preservation of the posterior white columns
Blockage of end arteries within the brain by disease is quickly followed by neuronal death and necrosis. The surrounding neuroglia then usually proliferates and invades the area, producing a neuroglial scar or forming a cystic cavity.
B) Both statements are true.
Once the terminal branches of the cerebral arteries enter the brain substance, no further anastomoses occur.
During examination of a carotid angiogram, the contrast medium had filled the anterior and middle cerebral arteries but had failed to fill the posterior cerebral artery. Careful following of the contrast medium showed it to enter the posterior communicating artery but to extend no farther. Explain this phenomenon in a normal person.
The posterior communicating artery is the site at which the streams of blood from the internal carotid and vertebral arteries on the same side come together, and since their pressures at this point are equal, they do not mix.
A 45-year old man was diagnosed with occlusion of the left posterior cerebral artery. Which of the following findings below is not consistent with this diagnosis?
C) Right-sided homonymous hemianopia
It should be right-sided homonymous hemianopia with sparing of the macular region.
The presence of a mild fleeting right-sided hemiparesis could be explained by a temporary occlusion of a branch of the left posterior cerebral artery to the left cerebral peduncle.
Atheromatous plaques tend to occur where the main arteries divide or where the arteries suddenly curve. All of the following are examples of such sites in the cerebral arteries, except:
A) Where the posterior cerebral artery passes around the lateral side of the superior cerebellar peduncle
It should be where the posterior cerebral artery passes around the lateral side of the superior cerebral peduncle.
True or False: Occlusion of the basilar artery will result in bilateral motor and sensory losses and involvement of the cranial nerves and cerebellum on both sides of the body.
True
The basilar artery contributes to the blood supply of both sides of the brain through the two posterior cerebral arteries and the many branches to both sides of the brainstem.
A 36-year-old man visited his physician with a complaint that on three occasions during the past 6 months, he had fainted at work. During careful questioning, the patient stated that on each occasion, he had fainted while sitting at his desk and while interviewing office personnel; he added that the person being interviewed sat in a chair immediately to the right of the desk. He said that before each fainting attack he felt dizzy; then, he lost consciousness only to recover within a few moments. The previous evening, he had a similar dizzy spell when he turned his head quickly to the right to talk to a friend in the street. The physician noted that the patient wore a stiff collar that was rather close fitting. When the physician commented on this, the patient stated that he always wore this type of collar to work. No abnormal physical signs were found. What is the most likely diagnosis of this patient?
D) Carotid sinus syndrome
The carotid sinus, situated at the proximal end of the internal carotid artery, is extremely sensitive to changes in arterial blood pressure. Distention of the arterial wall causes a reflex slowing of the heart rate and a fall in blood pressure.
It has been estimated that irreversible changes start to occur in the cerebral nervous tissue about _____ minutes following complete arrest of cerebral blood flow.
A) 4
This figure may be higher if the patient's body had been cooled.
A 62-year-old man with a history of hypertension visited his physician because the day before he had temporarily lost the sight in his right eye. He explained that the sight loss was partial and lasted about half an hour. On close questioning, the patient admitted that he had had similar episodes of blindness in the same eye during the previous 6 months, but they had lasted only a few minutes. The patient also mentioned that there were days when he could not remember the names of people and things. He also had recently experienced severe right-sided headaches. When asked about his activities, he said that he could not walk as well as he used to, and his left leg sometimes felt weak and numb. While performing a careful physical examination, the physician heard with his stethoscope a distinct systolic bruit over the right side of the neck. Given that the patient has vascular disease of the brain, which artery is likely to be involved in the disease process?
B) Right internal carotid artery
The impairment of vision of the right eye with motor symptoms in the left leg strongly suggests partial occlusion of the right internal carotid artery. When these are coupled with impairment of memory and a systolic bruit over the right internal carotid artery, the diagnosis is almost certain. The right-sided headaches are also common symptoms in this condition.
A 26-year-old man, on leaving a bar after a few drinks, stepped into the road at 1:00 AM and was struck by a passing car. Fortunately, the car was traveling slowly and struck the patient’s head a glancing blow. One hour later, a policeman found the patient unconscious on the sidewalk. Physical examination at the local hospital found that the patient had recovered consciousness for a few minutes but then had quickly relapsed into an unconscious state. The right pupil was dilated, and the muscle tone of the left leg was found to be less than normal. A positive Babinski sign was obtained on the left side. Examination of the scalp showed a severe bruise over the right temple, and a lateral radiograph of the skull showed a fracture of the anterior inferior angle of the parietal bone. A CT scan showed a dense area extending from anterior to posterior along the inner table of the right parietal bone. What is the diagnosis? Let us suppose that the equipment for performing a CT scan was unavailable and that it was decided to perform a lumbar puncture; this test revealed a raised cerebrospinal fluid pressure, and the fluid was very slightly blood stained. What is the most likely diagnosis of this patient?
B) Extradural hemorrhage
This patient had a right-sided extradural hemorrhage due to a fracture of the anterior part of the parietal bone, which tore the anterior division of the right middle meningeal artery. The history of the patient being found unconscious and then recovering consciousness for a period only to relapse into unconsciousness is a characteristic finding. The initial trauma usually is responsible for the initial loss of consciousness. The relapse into an unconscious state is due to the accumulation of a large blood clot under arterial pressure outside the meningeal layer of dura. This is responsible for the dilated pupil on the right side due to indirect pressure on the right oculomotor nerve. The pressure on the right precentral gyrus causes the hemiplegia and weakness of the left leg; it also causes the positive Babinski sign on the left side. The presence of a large blood clot in the intracranial cavity was easily recognized on a CT scan. The presence of the clot was also responsible for the raised cerebrospinal fluid pressure. The slight blood staining of the fluid obtained from a spinal tap was due to a small leakage of blood from the extradural space into the subarachnoid space at the fracture site.
A 50-year-old woman complaining of headaches, drowsiness, and mental confusion visited her physician. On close questioning, the patient distinctly remembered striking her head against a closet door when bending down 3 weeks previously. A CT scan revealed the presence of a large space-occupying lesion over the right frontal lobe of the brain. What is the possible diagnosis?
B) Chronic subdural hematoma
This patient had a chronic subdural hematoma following trauma to the head 3 weeks previously. This resulted from one of the superior cerebral veins tearing at its point of entrance into the superior sagittal sinus. The blood accumulated under low pressure between the dura and the arachnoid. The headaches, drowsiness, and mental confusion were due to the raised intracranial pressure.
The following statements concern the blood supply to the brain:
C) The circle of Willis is formed by the anterior cerebral, the internal carotid, the posterior cerebral, the basic, and the anterior and posterior communicating arteries.
The cerebral arteries anastomose on the surface of the brain.
There are no anastomoses between the branches of the cerebral arteries once they have entered the substance of the brain.
The main blood supply to the internal capsule is from the central branches of the middle cerebral artery.
The areas of the cerebral cortex listed below receive their arterial supply as indicated:
C) The precentral gyrus (face area) is supplied by the middle cerebral artery.
The cuneus is supplied by the posterior cerebral artery.
The inferior temporal gyrus is supplied by the posterior cerebral artery.
The Wernicke area is supplied by the middle cerebral artery.
The arteries listed below arise from the main stem arteries as indicated:
B) The posterior spinal artery arises from the vertebral artery.
The ophthalmic artery is a branch of the internal carotid artery.
The pontine arteries are branches of the basilar artery.
The posterior inferior cerebellar artery is a branch of the vertebral artery.
The veins listed below drain into the venous sinuses indicated:
D) The inferior sagittal sinus drains into the straight sinus.
The superior cerebral veins drain into the superior sagittal sinus, while the great cerebral veins drain into the straight sinus.
The superior cerebellar veins drains into the straight sinus, the transverse sinus, and the occipital sinus.
The spinal veins drain into the internal vertebral venous plexus.
The following statements concern the cerebral blood flow:
B) One of the most powerful vasodilators of cerebral blood vessels is carbon dioxide.
The sympathetic postganglionic fibers exert very little control over the diameter of the cerebral blood vessels.
It varies only slightly with changes in the general blood pressure.
The blood flow for a particular area of nervous tissue following occlusion of a cerebral artery depends on the adequacy of the collateral circulation.
The following statements concern cerebral ischemia:
D) Irreversible cerebral damage starts to occur after the cerebral blood flow has ceased for about 4 minutes.
Atheromatous degeneration of a cerebral artery may cause degeneration of the nerve cells in the avascular area and proliferation of the microglial cells in the surrounding area.
Neuronal function ceases after the blood flow has stopped for about 1 minute.
Cooling of the patient's body following a cerebrovascular accident slows down cerebral degeneration.
Shock occurring as the result of severe physical trauma can result in cerebra ischemia.
Match the numbered arteries listed below with the appropriate lettered arteries. Each lettered option may be selected once, more than once, or not at all.
a.) Middle cerebral artery
b.) Anterior communicating artery
c.) Posterior cerebral artery
d.) Basilar artery
e.) None of the above
1 - anterior communicating artery
2 - posterior cerebral artery
3 - none of the above (left vertebral artery)
4 - basilar artery
5- none of the above (right posterior communicating artery)
6- right middle cerebral artery
The following statements concern the blood supply to the spinal cord:
B) The spinal cord veins communicate with the veins of the brain and the venous sinuses.
The arteria radicularis magna (artery of Adamkiewicz) arises from the aorta in the lower thoracic or upper lumbar vertebral levels.
The anterior spinal artery is single but usually arise from both vertebral arteries.
The spinal arteries are reinforced by radicular arteries, which are branches of local arteries.
A 58-year-old man, while eating his evening meal, suddenly complained of a severe headache. Moments later, he slumped forward and lost consciousness. On being admitted to the hospital, the examining physician could have found the following physical signs except:
B) The right abdominal reflexes were absent, and there was a positive Babinski response on the left side.
A positive Babinski sign was present on the right side. Muscle tone of the limbs may be less on the right side than on the left.
A 58-year-old man, while eating his evening meal, suddenly complained of a severe headache. Moments later, he slumped forward and lost consciousness. He was admitted to the hospital. Three days later, the patient regained consciousness, and the following additional signs could have become apparent, except:
C) The upper and lower parts of the right side of his face were paralyzed.
The muscles of the upper part of the face on the right side are not affected by a lesion involving the upper motor neurons on the left side of the brain. This is due to the fact that the part of the facial nucleus of the seventh cranial nerve that controls the muscles of the upper part of the face receives corticonuclear fibers from both cerebral hemispheres.
A 58-year-old man, while eating his evening meal, suddenly complained of a severe headache. Moments later, he slumped forward and lost consciousness. He was admitted to the hospital. During the next 2 weeks, the following signs could have developed, except:
C) The muscles on the left side exhibited hypotonia.
The cerebral lesion was on the left side of the brain, and the muscles of the left leg were completely unaffected by the vascular accident.
A 58-year-old man, while eating his evening meal, suddenly complained of a severe headache. Moments later, he slumped forward and lost consciousness. He was admitted to the hospital. The neurologist in charge of this patient interpreted the findings as follows. All his interpretations were likely to be correct, except:
A) The depth of coma is unrelated to the extent of arterial blockage.
The depth of coma is related to the extent of the arterial blockage.
A 58-year-old man, while eating his evening meal, suddenly complained of a severe headache. Moments later, he slumped forward and lost consciousness. He was admitted to the hospital. The following physical signs and known anatomical data strongly suggest the involvement of the left middle cerebral artery, except:
B) The central branches of the middle cerebral artery do not supply the lentiform nucleus, the caudate nucleus, and the internal capsule.
The central branches of the right middle cerebral artery do supply the right lentiform and caudate nuclei and the right internal capsule.
A 60-year-old man was admitted to the emergency department, complaining of the sudden onset of excruciating, sharp, tearing pain localized to the back of the chest and the back. After a thorough physical and radiologic examination, a diagnosis of dissection of the descending thoracic aorta was made. Within a few hours, the patient started to experience “girdle” pain involving the fourth thoracic dermatome on both sides. Later, he was found to have bilateral thermoanesthesia and analgesia below the level of the fourth thoracic dermatome. Position sense, vibration, and light touch remained normal. Complete spastic paralysis of both legs quickly developed. The sudden onset of "girdle" pain in this was most likely caused by:
C) Blockage of the origins of the posterior intercostal arteries that give rise to the segmental spinal arteries by the aortic dissection
In the thoracic region, the posterior intercostal arteries arise directly from the thoracic aorta and can be blocked by a blood clot as the aortic dissection progresses. The segmental spinal arteries, which are branches of the posterior intercostal arteries, give origin to the radicular arteries that supply the spinal nerves and their roots. If these arteries are compromised, severe pain is experienced in the distribution of the spinal nerves involved and, hence, the “girdle” pain.
A 60-year-old man was admitted to the emergency department, complaining of the sudden onset of excruciating, sharp, tearing pain localized to the back of the chest and the back. After a thorough physical and radiologic examination, a diagnosis of dissection of the descending thoracic aorta was made. Within a few hours, the patient started to experience “girdle”pain involving the fourth thoracic dermatome on both sides. Later, he was found to have bilateral thermoanesthesia and analgesia below the level of the fourth thoracic dermatome. Position sense, vibration, and light touch remained normal. Complete spastic paralysis of both legs quickly developed. The development of bilateral thermoanesthesia and analgesia below the level of the fourth thoracic segment of the cord and the later development of paraplegia could be caused by:
C) Absent circulation in the anterior spinal artery
The blood supply to the spinal cord is meager, and if the segmental arteries that reinforce the anterior and posterior spinal arteries are compromised, ischemia of the spinal cord could follow. In this patient, the circulation in the anterior spinal artery ceased, and the blood supply to the anterior two-thirds of the spinal cord was cut off. This would explain the sudden development of bilateral thermoanesthesia and analgesia (spinothalamic tracts in both lateral white columns) and the paraplegia (corticospinal tracts in both lateral white columns).The sparing of the sensations of position, vibration, and light touch, which travel in the fasciculus gracilis and fasciculus cuneatus, can be explained by the fact that the posterior white columns are supplied by the posterior spinal arteries, in which the circulation was adequate.
True or False: The intermediate zone will form the gray matter of the spinal cord, whereas the marginal zone will form the white matter.
True
True or False: The neuroblasts in the alar plate will form the motor cells of the anterior column, while the neuroblasts in the basal plate will become the sensory cells of the posterior column.
False
The neuroblasts in the basal plate will form the motor cells of the anterior column, while the neuroblasts in the alar plate will become the sensory cells of the posterior column.
During the first 2 months of intrauterine life, the spinal cord is the same length as the vertebral column. Thereafter, the developing vertebral column grows more rapidly than the spinal cord; thus, at birth, the coccygeal end of the cord lies at the level of the first lumbar vertebra.
D) Only the first statement is true.
Thereafter, the developing vertebral column grows more rapidly than the spinal cord; thus, at birth, the coccygeal end of the cord lies at the level of the third lumbar vertebra.
True or False: The obliquely coursing anterior and posterior roots of the spinal nerves and the filum terminale,which now occupy the lower end of the vertebral canal,collectively form the conus medullaris.
False
The obliquely coursing anterior and posterior roots of the spinal nerves and the filum terminale,which now occupy the lower end of the vertebral canal,collectively form the cauda equina.
All of the following statements are true the development of brain, except:
C) The tectum, tegmentum, and hypophysis cerebri are derived from mesencephalon.
The tectum, tegmentum, and crus cerebri are derived from mesencephalon. Hypophysis cerebri is also known as the pituitary gland.
The neurons of the basal plate of the medulla oblongata form the motor nuclei of cranial nerves IX, X, XI, and XII and are situated in the floor of the fourth ventricle medial to the sulcus limitans. Meanwhile, the neurons of the alar plate form the sensory nuclei of cranial nerves V, VIII, IX, and X and the gracile and cuneate nuclei.
B) Both statements are true.
Which of the following is not true about the development of pons?
B) The neurons of the alar plate form the spinal nucleus of cranial nerve V, a sensory nucleus of cranial nerve VII, and the vestibular and cochlear nuclei of cranial nerve VIII.
The neurons of the alar plate form the main sensory nucleus of cranial nerve V, a sensory nucleus of cranial nerve VII, and the vestibular and cochlear nuclei of cranial nerve VIII.
Which of the following is not true about the development of cerebellum?
D) At the end of fourth month, fissures develop on the surface of the cerebellum, and the characteristic gyri of the adult cerebellum gradually develop.
At the end of fourth month, fissures develop on the surface of the cerebellum, and the characteristic folia of the adult cerebellum gradually develop.
Which of the following is not true about the development of midbrain?
A) The neuroblasts in the alar plates differentiate into the sensory neurons of the superior colliculi, which are associated with visual reflexes, and the inferior colliculi, which are associated with auditory reflexes.
The infundibulum develops as a diverticulum from the roof of the diencephalon. From it will originate the stalk and pars nervosa of the hypophysis.
C) Only the second statement is true.
The infundibulum develops as a diverticulum from the floor of the diencephalon.
True or False: The corpus callosum is the first commissure to develop.
False
The anterior commissure is the first commissure to develop. It connects the olfactory bulb and the temporal lobe of the cortex on one side with the same structures of the opposite hemisphere.
True or False: The anterior commissure is the second commissure to develop.
False
The fornix is the second commissure to develop. It connects the cortex of the hippocampus in each hemisphere.
True or False: The corpus callosum, the largest and most important commissure, is the third commissure to develop.
True
Its first fibers connect the frontal lobes of both sides and, later, the parietal lobes.
Which of the following is not true about the myelination in the central nervous system?
D) At birth, the brain is largely myelinated.
At birth, the brain is largely unmyelinated. In the newborn, there is very little cerebral function and motor reactions such as respiration, sucking, and swallowing are essentially reflex.
Which of the following is not true about spina bifida occulta?
B) Most cases are symptomatic and are diagnosed by chance when the vertebral column is x-rayed.
Most cases are symptomless and are diagnosed by chance when the vertebral column is x-rayed.
Which of the following is not true about myelocele?
B) None of these
True or False: In syringomyelocele, a meningomyelocele is pressent, and in addition, the central canal of the spinal cord at the level of the bony defect is grossly constricted.
False
In syringomyelocele, a meningomyelocele is pressent, and in addition, the central canal of the spinal cord at the level of the bony defect is grossly dilated.
In hydrocephalus, the ventricles of the brain become markedly dilated. This ventricular expansion occurs largely at the expense of the white matter, and the neurons of the cerebral cortex are mostly spared.
A) Both statements are true.
.This results in the preservation of cerebral function, but the destruction of the tracts, especially the corticobulbar and corticospinal tracts, produces a progressive loss of motor function.
All of the following are true about anencephaly, except:
D) Most anencephalic infants can live up to a year.
Most anencephalic infants are stillborn or die shortly after birth.
True or False: The development and closure of the neural tube are normally completed within 30 days.
False
The development and closure of the neural tube are normally completed within 28 days.
A 10-year-old boy fell off his bicycle and hurt his back. Following a complete physical examination in the emergency department, nothing abnormal was found. An x-ray examination, however, revealed the complete absence of the spine and laminae of the fifth lumbar vertebra. Which of the following is the likely diagnosis?
C) Spina bifida occulta
This patient has spina bifida occulta involving the fifth lumbar vertebra. The condition is a result of failure of the mesenchyme to grow between the neural tube and the surface ectoderm and form the vertebral arch; the vertebral canal remains open posteriorly. The defect, therefore, has existed since before birth and could not be seen or felt on physical examination because it was covered by the postvertebral muscles. The spinal cord and spinal nerve roots usually are normal. No treatment is required.
A male child was delivered normally to a 20-year-old woman. A pediatrician examined the infant and found a large swelling in the lower part of his back over the fourth and fifth lumbar vertebrae. On closer examination, the summit of the swelling had an oval raw area from which a clear fluid was discharging. The legs showed hyperextension of the knees, and the feet were held in the position of talipes calcaneus. What is the diagnosis?
C) Spina bifida myelocele
This child has a myelocele. In addition to the failure of the formation of the vertebral arches of the fourth and fifth lumbar vertebrae, the neural tube failed to close in this region. The oval raw area seen in this patient is the neural groove whose lips have not united. The central canal is discharging clear cerebrospinal fluid onto the skin surface. The deformities of the knee joints and feet are the result of the maldevelopment of the spinal cord in the lumbar region, with consequent interference with the innervation of certain muscle groups in the legs.
A 2-month-old girl was taken to a pediatrician because her mother was concerned about the size of her head. “She looks top-heavy,” she said. Examination showed the head to be large and globular in shape. The anterior fontanelle was greatly enlarged and extended posteriorly to the enlarged posterior fontanelle. The enlarged head contrasted markedly with the small face. Neurologic examination revealed some evidence of optic atrophy on both sides, and there was increased tone in the muscles of both lower limbs. What is the diagnosis?
B) Hydrocephalus
This child has hydrocephalus. A postmortem examination performed 1 year later showed that the cerebral aqueduct was not normally developed and consisted of a number of small tubules. This had resulted in the excessive accumulation of cerebrospinal fluid within the lateral and third ventricles of the brain. The distention of the ventricles, with the consequent enlargement of the brain and increased intracranial pressure, forced apart the bones of the cranial vault so that the head became greatly enlarged. The optic atrophy probably was caused by the stretching of the optic nerve on each side. The increased muscle tone of the lower limbs was almost certainly the result of destruction of the corticospinal and other descending tracts by the expanding lateral ventricles. Although in some cases the head ceases to enlarge spontaneously, in most patients the hydrocephalus is progressive, and death ultimately occurs. Surgical treatment of hydrocephalus may be attempted.
The following statements concern the neural tube:
A) The nerve fibers in the marginal zone become myelinated and form the white matter of the spinal cord.
It is lined by a single layer of pseudostratified columnar epithelial cells.
The neuroblasts migrate peripherally to form the intermediate zone.
The intermediate zone will form the gray matter of the spinal cord.
The repeated division of the matrix cells of the neural tube results in an increase in the length and diameter of the tube.
The following statements concern the neural crest cells:
D) They give rise to the posterior root ganglia.
They are formed from the lateral margin of the neural plate.
They form the neurons of the autonomic ganglia and the cells of the suprarenal medulla.
The Schwann cells of peripheral nerves are formed from neural crest cells.
The following statements concern the developing spinal cord:
C) The alar plates form the neurons in the posterior gray columns.
The nerve cells of the sympathetic outflow are formed from the basal plates.
At birth, the lower end of the spinal cord lies at the level of the third lumbar vertebra.
The meninges surrounding the spinal cord are developed from the mesenchyme that surrounds the neural tube.
The following statements concern the development of brainstem:
B) The cerebellum is formed from the dorsal part of the alar plates of the metencephalon.
The neurons of the deep cerebellar nuclei are derived from the matrix cells lining the cavity of the hindbrain vesicle.
The neuroblasts in the basal plates will form the nuclei of the trochlear and oculomotor nerves.
The neuroblasts of the superior and inferior colliculi are formed from the neurocytes in the alar plates.
The pons arises from the anterior part of the metencephalon, with cellular contribution from the alar part of the myelencephalon.
The following statements concern the fate of the forebrain vesicle:
D) The pars nervosa of the hypophysis is formed from the floor of the diencephalon.
The optic vesicle grows out of the forebrain vesicle.
The thalamus is formed from the alar plates in the lateral walls of the diencephalon.
The lamina terminalis is formed from the rostral end of the telencephalon.
The hypothalamic nuclei are formed from the alar plates of the diencephalon.
The following statements concern the development of cerebral hemispheres:
A) The internal capsule is formed by the developing ascending and descending tracts growing between the developing thalamus and caudate nucleus medially and the lentiform nucleus laterally.
The corpus striatum is formed from the proliferation of the matrix cells lining the floor of the forebrain vesicle.
The interventricular foramen is formed by the cavity of the telencephalon.
The choroid plexus of the lateral ventricle is formed by vascular mesenchyme covered by ependymal cells.
The neurons of the cerebral cortex develop from matrix cells lining the cavity of the cerebral hemisphere. These cells produce a large number of neuroblasts that migrate out into the marginal zone.
The following statements concern the development of myelination in the brain:
B) Myelination of the nerve tracts is largely complete by the end of the second year.
Myelination begins at about sixth month of fetal life.
In the developing brain, the sensory fibers are myelinated first.
The process of myelination is not haphazard but systematic, occurring in different nerve fibers at specific times.
In the developing brain, myelination is carried out by oligodendrocytes and not by neurons.
The following statements concern the condition of spina bifida:
D) In a myelocele, the neural tube does not close in the region of the defect.
The most common form of spina bifida is spina bifida occulta.
The condition occurs most often in the lower thoracic, lumbar, and sacral regions.
Most cases of spina bifida occulta require no treatment.
Spina bifida is one of the more common congenital anomalies of the central nervous system.
A 6-month-old girl was seen by the plastic surgeon because of the presence of a swelling at the root of the nose. The mother said that she had noticed the swelling when the child was born and that since then, it had gradually increased in size. The surgeon examined the child and found the following likely signs, except:
A) The pulse did not coincide with the pulse felt over the anterior fontanelle of the skull.
In a cephalic meningocele, the cerebrospinal fluid within the swelling is in direct communication with that in the subarachnoid space. The pulsation of the swelling is produced by the pulse wave of the cerebral arteries through the cerebrospinal fluid. This pulse wave will coincide with the pulse felt over the anterior fontanelle of the skull.
A 6-month-old girl was seen by the plastic surgeon because of the presence of a swelling at the root of the nose. The mother said that she had noticed the swelling when the child was born and that since then, it had gradually increased in size. The neurosurgeon was consulted, and the following possible additional findings were ascertained except:
C) Brain tissue is never found within the hernia.
Cranioschisis is characterized by a defect in the membranous bones of the skull through which meninges or meninges and neural tissue may protrude. The defect usually occurs in the midline in the occipital region or between the frontal and nasal bones. The condition is probably the result of anomalous formation and separation of the neural tube from the surface ectoderm of the embryo.
A patient presents with visual agnosia. Which of the following cortical regions is likely to be damaged?
C) Inferotemporal cortex
Visual agnosia is an inability to recognize objects in the absence of other problems like visual disturbance and memory loss. The inferotemporal cortex is responsible for the 'what' processing of object recognition (ventral stream) and is thus frequently damaged in patients with visual agnosia.
The primary visual cortex is responsible for initial processing of visual information, but damage to this area would likely cause cortical blindness rather than a specific cognitive deficit like visual agnosia.
The posterior parietal cortex is involved (amongst other things) with the 'where' processing of object recognition (dorsal stream). Patients with damage to this area may find it difficult to understand the spatial properties of objects but would retain their ability to recognize the object.
The hippocampus is involved in memory and emotional processing. Patients with hippocampal damage may find it difficult to learn new objects, but should not have problems recognizing objects they have already encountered prior to their brain damage.
Which cranial nerve exits on the dorsal surface of the brainstem?
A) CN IV
CN VI, the trochlear nerve is the only cranial nerve which exits the dorsal aspect of the brain stem, just below the inferior colliculus.
The pathway of which tract runs through the corona radiata?
B) Corticospinal tract
The corona radiata is a white matter sheet that continues ventrally as the internal capsule and dorsally as the centrum semiovale.
Motor fibres run from the motor cortex to the internal capsule via the corona radiata and go on to form the corticospinal tract.
Which of the following is most true of cerebral arteriovenous malformations?
B) They are congenital in origin.
Cerebral arteriovenous malformations (AVMs) are congenital tangles of pial vasculature resulting in arterio-venous shunting of blood. A nidus, made of shunting arterioles and inter-connected venous loops, is fed by one or more - usually ectatic - arteries, and drained by one or more veins.
AVMs are frequently asymptomatic, but can present with seizures, headache, vascular steal phenomena and intracranial haemorrhage. Increased risk of haemorrhage is associated with the presence of intranidal aneurysms, venous stenosis, arterial ectasis, and old age - interestingly, AVM size is not thought to be related to haemorrhage risk.
While CT and MRI scans can show valuable signs of AVM (viz. hyperdensity and possible calcification on CT, and mesh of flow voids with enlarged draining veins on MRI), digital subtraction angiography (DSA) scans are the gold-standard modality to enable accurate definition of the nidus size and architecture. DSA can identify feeding arteries, the presence of deep or superficial cortical draining veins, flow rate, intranidal aneurysms and venous stenosis with exquisite detail.
AVMs are relatively uncommon - around ten times less common than cerebral aneurysms. Note however that AVMs are in fact the most common symptomatic vascular malformation.
All of the following structures pass through the posterior compartment of the foramen magnum, except:
F) Tectorial membrane
The tectorial membrane, apical ligament, and upper band of cruciate ligament pass through the anterior compartment of the foramen magnum.
Which of the following is the most likely to be responsible for a subdural haemorrhage?
D) Tearing of bridging veins
Subdural haematoma (SDH), is usually associated with traumatic brain injury. Blood gathers between the inner layer of the dura mater and the arachnoid mater, usually due to tearing of bridging veins which cross the subdural space. Subdural hemorrhages may cause an increase in intracranial pressure (ICP), which can cause compression of and damage to delicate brain tissue.
Rupture of the middle meningeal artery would result in an extradural hematoma, as it is located outside of the dura mater.
Rupture of the middle or anterior cerebral arteries would result in an intracerebral hemorrhage, within the brain tissue itself.
Which of the following structures is responsible for the absorption of cerebrospinal fluid (CSF) into the venous system?
D) Arachnoid granulations
Cerebrospinal fluid (CSF) is reabsorbed into the venous systems by structures called arachnoid granulations. They are villi of the arachnoid mater which protrude in bunches into the venous structures (sinuses) of the cerebral cavity.
CSF is made by the ependymal cells in the choroid plexus. Choroid plexi are located in all of the ventricles in the brain. The CSF serves to create an optimal extracellular environment for the cells of the brain and central nervous system both by transporting nutrients and removing waste products. Hence, continuous production by the choroid plexus and reabsorption by the arachnoid granulations is essential in maintaining this homeostasis.
The cavernous sinus is one of the venous sinuses of the cranial cavity. It is located posterior to the orbit and a number of important structures run through it. These include the internal carotid artery and cranial nerves III, IV, V1, V2 and VI. Located in a central position in the cavernous sinus is the pituitary gland. This is why tumours of the pituitary gland often affect sight and eye movements. It has no role in CSF absorption.
The pia mater is the innermost layer of the cranial meninges. It is delicate in nature, highly vascularised and lies closest to the cerebral cortex. It has no role in CSF circulation.
Which of the following cranial nerves is surrounded by all three meningeal layers?
E) Optic nerve
The hypothalamus, which is located below the thalamus and is part of the limbic system, is a portion of the brain that contains multiple small paired nuclei. These nuclei are the centre for many physiological processes. Which of the following nuclei is involved in the control of circadian rhythms?
D) Suprachiasmatic nucleus
The suprachiasmatic nucleus controls circadian rhythms and receives input from the retina.
The preoptic nucleus contains sexually dimorphic nuclei which regulate the release of gonadotropic hormones.
The posterior nucleus is involved in thermal regulation, specifically the conservation of heat, and its destruction results in an inability to thermoregulate.
The supraoptic nucleus regulates water balance through the release of ADH (vasopressin), and its destruction results in diabetes insipidus.
The anterior nucleus is involved in thermal regulation, specifically the dissipation of heat, and its destruction results in hyperthermia.
Subdural hematoma are found between which of the following layers?
A) Arachnoid mater and meningeal layer of dura mater
A subdural haematoma is a collection of blood between the meningeal layer of the dura mater and the arachnoid mater. It usually results from tears in bridging veins that cross the subdural space.
What is the major nucleus of the visual pathway?
D) Lateral geniculate nucleus
The lateral geniculate nucleus is the major nucleus within the visual pathway of the brain. As a relay centre in the thalamus, the LGN helps connect the optic tract to the dorsal optic radiations of Meyer's and Baum's loops in the temporal and parietal lobes of the brain.
The medial geniculate nucleus is associated with auditory processing. It is found in the thalamus, inferior to the LGN, and connects the inferior colliculus signals to the auditory cortex.
The olfactory bulb lies atop the cribriform plate of the anterior cranial fossa. Olfactory hair cells synapse here, connecting to the olfactory tract for processing in the brain - mainly the entorhinal cortex.
Nucleus basalis of Meynert is a system of neurons located in the basal forebrain that produce acetylcholine. They have numerous connections to the cortical structures of the brain, which help transport the acetylcholine produced here.
The spinal trigeminal nucleus is a region of the brainstem and upper cervical cord that receive pain, temperature and crude touch input from the ipsilateral face. It then sends this information to the ventral posteromedial nucleus of the thalamus, where it synapses to the primary somatosensory cortex.
Which is the primary neurotransmitter involved in the formation of memory?
D) Glutamate
Long term memory development occurs through long term potentiation, which is the process of increasing the efficiency of a synapse through the repeated activity of that particular synapse. It occurs through the excitatory action of glutamate binding to NMDA receptors. By binding to the NMDA it initiates genetic transcription factors to create more AMPA receptors, which is also activated by glutamate. By creating more ion channels, the neurone has a greater chance of being excited the next time the synapse is activated. Glutamate is one of the primary neuroexcitatory transmitters.
Noradrenaline is both a neurotransmitter and a hormone, which acts to initiate the “flight or fight” response. In the brain, it is created in the locus coeruleus in the pons to increase arousal, alertness and it can enhance the formation and retrieval of memory.
GABA (gamma-aminobutyric acid) is an important inhibitory neurotransmitter, bringing about the depression of neuronal excitability. Drugs such and benzodiazepines and alcohol bring about neurodepression through enhancing the action of GABA.
The primary function of acetylcholine is as a neurotransmitter at the neuromuscular junction, although it also acts within the sympathetic and parasympathetic nervous systems. Finally, acetylcholine acts within the brain and is involved with motivation and attention.
Dopamine is a monoamine neurotransmitter which also functions as a neurotransmitter and a hormone. Dopaminergic action activates the reward pathways as well as being transmitted in the basal ganglia to regulate motor control.
General visceral afferents (GVAs) within cranial nerves IX and X are responsible for innervation of the carotid and aortic bodies. Which brainstem nucleus do they synapse within?
E) Solitary nucleus
Solitary nucleus of the medulla is the point of synapse for general visceral afferents running within cranial nerves IX and X, as well as gustatory (taste) afferents running within cranial nerves VII (chorda tympani), IX, and X.
Nucleus ambiguus is the branchial motor nucleus for cranial nerves IX and X.
Spinal trigeminal nucleus is the somatosensory nucleus for cranial nerves V (pain and temperature only), IX, and X.
Chief sensory nucleus is the somatosensory nucleus for cranial nerve V (fine touch, pressure, vibration).
Dorsal nucleus of vagus is the pre-ganglionic parasympathetic nucleus for cranial nerve X.
Which part of a spinal nerve contains only motor (efferent) nerve fibres?
D) Ventral root
The ventral roots contain only motor (efferent) nerve fibres and communicate motor information from the brain.
The dorsal roots contain only sensory (afferent) nerve fibres and communicate sensory information to the brain.
The ventral ramus branches from the spinal nerve and communicates sensory, visceral motor and somatic motor information to and from the ventrolateral body surface, the limbs and various structures in the body wall.
The dorsal ramus also branches from the spinal nerve and communicates visceral motor, somatosensory and somatic motor information to and from the posterior aspect of the body.
The rami communicantes contains autonomic nerves.
The stria terminalis runs along which ventricle?
B) Lateral ventricle
The amygdala projects fibres to the stria terminalis which runs in the wall of the lateral ventricle and projects fibres to the ventromedial nucleusof the hypothalamus.
The optic nerve consists of fibres from ___________ nasal and temporal retinal fields.
D) Ipsilateral
The optic nerve consists of ipsilateral temporal and nasal retinal fibres.
This is to say that each optic nerve contains complete nasal and temporal retinal information for a single eye on the same side (left optic nerve for left eye, right optic nerve for the right eye).
The optic nerve does not contain contralateral fibres - a phenomenon only seen after the optic chiasm. This is discussed further in subsequent questions.
The superior and inferior retinal fibres compose part of the nasal and temporal retinal fields. These are not the most correct answer.
The motor fibers of this cranial nerve are derived from the so-called port minor.
C) Trigeminal nerve
The motor fibres of cranial nerve V3 are derived from a minor branch of the trigeminal complex known as portio minor. This 'minor portion' of the trigmenal complex originates in the trigeminal motor nucleus of the pons, and travels through foramen spinous with the middle meningeal artery.
In cases of trigeminal neuralgia where vascular compression is present, which of the following vessels is most commonly responsible?
D) Superior cerebellar artery
Most commonly, it is the superior cerebellar artery that is responsible for trigeminal neuralgia - in cases where compression can be found. The artery typically passes against the root entry zone of the nerve as it leaves the pons. Less frequently the anterior inferior cerebellar artery or the superior petrosal veins can be the cause of compression.
Which of the following cranial nerves is most likely to be compressed by increased intracranial pressure?
A) CN VI
The abducens nerve (CN VI) has a long intracranial course, originating from the junction of the pons and the medulla. It is felt that this long course makes the nerve more susceptible to compression when there is raised intracranial pressure, as it is often the first cranial nerve deficit to be noted.
What is the anatomical location of Broca's area?
C) Inferior frontal gyrus
Broca's area is a region in the frontal lobe of the dominant hemisphere that is involved in speech production. It is made up of Brodmann's areas 44 and 45.
Wernicke's area is a region located in the superior temporal gyrus of the temporal lobe. It is involved in the comprehension of written and spoken language. It is thought be located in Brodmann area 22.
Which of the following connects the fourth ventricle to the cistern magna?
C) Foramen of Magendie
The foramen of Monro, which is also known as interventricular foramen, connects the third ventricle and the lateral ventricles.
The foramen of Lushka is a natural aperture at the cerebellopontine angle between the fourth ventricle and the subarachnoid space.
The aqueduct of Sylvius, which is also known as cerebral aqueduct, connects the third ventricle to the fourth ventricle.
What is the effect of inhibition of sympathetic receptors in the posterior hypothalamus during fever?
C) Vasodilation of blood vessels in the skin
Sympathetic innervation causes stimulation of alpha receptors which causes vasoconstriction, therefore inhibition of sympathetic receptors in the posterior hypothalamus during fever causes vasodilatation of blood vessels in the skin.
Sweating is caused by activation of the sympathetic cholinergic neurons whereas piloerection and shivering are compensatory mechanisms during hypothermia.
Which of the following malignancies might cause a facial nerve palsy?
A) Mucoepidermoid carcinoma of the parotid salivary gland
The facial nerve runs through the parotid gland. Thus any growth within the parotid gland, such as a neoplasm, can compress the facial nerve and cause a palsy. An `acoustic neuroma (a tumour of cranial nerve VIII) may also compress the facial nerve due to their close proximity. Whilst malignancies account for around 2.5% of facial nerve palsies, the most common cause is Bell's palsy, an idiopathic condition that has some association with viruses. Other causes might include trauma or infection.
Adenocarcinoma of the submandibular gland is a rare head and neck malignancy and unlikely to interfere with the facial nerve due to its anatomical location.
HPV is an important cause of oropharyngeal cancer but has no involvement with the path of the facial nerve.
Squamous cell carcinomas of the oral cavity and tongue are most often due to smoking and do not involve the facial nerve.
Cerebellar oligodendromas are malignant incurable brain tumours that are slow-growing. They are treated with chemotherapy, radiotherapy and surgical resection. Depending on the grade of the tumor, survival can often extend beyond a decade.
Approximately 90% of the fibers of the optic tract synapse in the lateral geniculate nucleus. The remainder form which of the following structures?
C) Brachium of superior colliculus
10% of the fibers in the optic tract form the brachium of the superior colliculus, which does not relay in the thalamus, but passes into the superior colliculus where fibers synapse (many in the pretectal nucleus).
The pretectum is a structure in the midbrain composed of seven nuclei and comprises part of the subcortical visual system. Through reciprocal bilateral projections from the retina, it is involved primarily in mediating behavioural responses to acute changes in ambient light such as the pupillary light reflex, the optokinetic reflex, and temporary changes to the circadian rhythm. The anterior pretectal nucleus has also been found to mediate somatosensory and nociceptive information.
The inferior colliculus is the principal midbrain nucleus of the auditory pathway and receives input from several peripheral brainstem nuclei in the auditory pathway, as well as inputs from the auditory cortex.
Which area of the brain is involved in the experience of pleasure?
E) Ventral tegmental area
The ventral tegmental area consists of dopamine pathways that are linked to pleasure. Damage to this area can result in addictive behaviours such as substance misuse or gambling.
The amygdala is associated with fear responses and aggression.
The cingulate gyrus is associated with making connections between emotionally important events, such as linking a particular smell with a memory.
The hippocampus is associated with long term memory.
The hypothalamus is part of the endocrine system and releases hormones.
What is the function of the circuit of Papez?
B) Episodic memory
The Circuit of Papez is a network that connects the hippocampus, fornix, mammillary bodies, anterior thalamic nuclei, and cingulate gyrus.
It is thought that memories are distributed within the circuit. Damage to structures within this circuit is known to lead to episodic memory deficits.
Korsakoff's syndrome is associated with atrophy of the mammillary bodies whilst hippocampal atrophy is found in Alzheimer's disease.
Which part of the thalamus is important for motor control?
C) Ventral anterior nuclei
The ventral lateral and ventral anterior nuclei are thought to be involved in motor control. They receive input from the cerebellum and the basal ganglia, and transmit this to the motor cortex.
The posterior nuclei contain the medial and lateral geniculate nuclei, which relay auditory and visual sensory input, respectively.
The reticular nucleus is involved in the regulation of thalamic signals and may play a role in disinhibiting thalamic cells to allow for the initiation of movement.
The ventral posterior lateral nuclei processes somatosensory information.
The axons of which of the following retinal cells make up the optic nerve?
D) Ganglion cell axons
Ganglion cell axons form the optic nerve which carries information to higher regions of CNS.
There are five types of neurons in the retina: photoreceptors, bipolar cells, ganglion cells, horizontal cells, and amacrine cells.
Light is detected by photoreceptor cells which contain light-sensitive photopigment, signals are then transduced in the retina and relayed to the brain from photoreceptors to bipolar cells to ganglion cells and onto higher regions of the CNS via the optic nerve.
After synapsing at the lateral geniculate nucleus, visual information passes through which optic pathways to reach the primary visual cortex of the occipital lobe?
E) Meyer and Baum loops
After synapsing on the lateral geniculate nucleus (LGN), the visual pathway travels through Meyer and Baum loops to reach the primary visual cortex. These loops are otherwise known as the optic radiations, and are visible in well-dissected deep brain specimens.
The Meyer loops (one in each hemisphere) travel from the LGN and laterally through the temporal optic radiation before synapsing on the calcarine sulcus.
The Baum loops (one in each hemisphere) travel from the LGN and move superiorly through the parietal optic radiation before synapsing on the calcarine sulcus.
The left Meyer loop transmits the left inferior retinal field from both eyes.
The right Meyer loop transmits the right inferior retinal field from both eyes.
The left Baum loop transmits the left superior retinal field from both eyes.
The right Baum loop transmits the right superior retinal field from both eyes.
Developmentally, one of the reasons for the digression of different parts of the visual pathway is the formation of the ventricles, specifically the lateral ventricles, which may 'push' the visual pathway aside in order to create a cistern large enough for cerebrospinal fluid to nourish the deep brain tissue. As a protective mechanism, it has been speculated that the deviation in pathways is to prevent small, localised injuries and pathology from interfering with the entire visual field.
The Meissner and submucosal plexuses are plexuses, not loops. They provide sensorimotor autonomic innervation to the gastrointestinal tract.
The femoral triangle is located in the upper medial thigh. It transmits the femoral vessels from the anterior compartment of the thigh to the posterior genicular space where they are named the popliteal vessels.
The lateral triangular space is found in the shoulder, as is formed by the teres major and minor muscles, as well as the long head of triceps brachii and humeral shaft.
The nasal visual field is perceived by the ________ retinal field.
A) Temporal
The nasal visual field is perceived by the temporal retinal field.
The temporal retinal field refers to the part of the retina lateral to the vertical meridian of the retina. The orientation of these retinal cells face 'medially' such that any image seen by this retinal field will be from a location medial to the eye.
Thus, the nasal retinal field perceives light and images from the temporal visual field. The same goes for the superior and inferior retinal fields, which perceive light and images from the inferior and superior visual fields respectively.
Which dopaminergic pathway is affected by Parkinson's disease?
A) Nigostriatal
Nigrostriatal pathway is a major dopaminergic pathway in the brain. Dysfunction can result in the classic symptoms of parkinsonism as well as dystonia, akathisia and tardive dyskinesia.
Mesolimbic pathway dysfunction can result in the "positive" symptoms of delusions and hallucinations seen in schizophrenia.
Mesocortical pathway dysfunction can result in "negative" symptoms of anergy and apathy seen in schizophrenia.
Tuberoinfundibular pathway dysfunction can result in galactorrhea and gynaecomastia in men
What type of nerve fibers are mainly activated as the lens relaxes during the accommodation reflex?
C) Parasympathetic nerves from the Edinger-Westphal nucleus
The ciliary muscle, which is the effector muscle in the accommodation reflex, is mainly innervated by parasympathetic neurons originating at the Edinger-Westphal nucleus. Parasympathetic stimulation of the ciliary muscles causes both the circular and longitudinal muscles of the ciliary muscle to contract. This relaxes the tendons of the lens, allowing it to relax and become thicker. This allows the eye to focus on closer objects.
The other effector muscle in the accommodation reflex is the medial rectus which converges the eyes. This is supplied by motor neurons in the oculomotor nerve, which originates from the oculomotor nucleus in the midbrain.
In which of the following retinal layers would the processes and synaptic contacts of retinal neurons most likely reside?
B) Inner plexiform layer
There are five types of neurons in the retina: photoreceptors, bipolar cells, ganglion cells, horizontal cells, and amacrine cells.
The cell bodies and processes of these neurons are stacked in alternating layers.
The cell bodies are located in the inner nuclear, outer nuclear, and ganglion cell layers.
The processes and synaptic contacts are located in the inner plexiform and outer plexiform layers.
The hippocampus is important for learning and _________ memory.
C) Spatial
The hippocampus is responsible for learning and spatial memory.
Also known as the brain "seahorse" from which its name translates, the hippocampus is central to the function of the limbic system. It is a longitudinal (sagittal) structure located deep to the temporal lobe of the brain, abutting the temporal horn of the lateral ventricle.
It is divided into three regions:
1. The ventral hippocampus functions in conditioning and affective processes.
2. The dorsal hippocampus is involved in spatial memory formation.
3. The intermediate hippocampus functions in part of both the ventral and dorsal hippocampi.
It has also been suggested that the left aspect of the hippocampus is involved in the recall of spatial memory.
The hippocampus is part of the limbic system, which is heavily involved in long-term memory production.
An accurate memory is a memory that is recalled in acute detail. There is no single macroscopic anatomical structure that defines the accuracy of memories. Rather, it appears to be a result of the repetitive use of memory pathways that evokes stronger subsequent recall.
Procedural memories are unconscious long-term memories of sequences of events relating to an action or behaviour, such as riding a bike. These memories are thought to be stored in the temporal cortex.
Episodic memories are thought to be stored in the neocortex of the temporal lobe. However, recent studies suggest that the hippocampus may be involved.
Working memory is the type of transient memory we use to store sequences such as phone numbers or the address of someone we just met. While the temporal lobe is involved, it is thought that working memories may utilise stronger, pre-formed memory pathways and allow axonal growth between pre- and post-synaptic neurons. If the memory is consolidated after repetition, the axonal connections strengthen. If the pathway is left unutilised, it is synaptically pruned.
Which of the following deficits in feature perception might result after a lesion in the magnocellular layers of the lateral geniculate nucleus (LGN)?
D) Akinetopsia
Thee magnocellular layers of the lateral geniculate nucleus (LGN) are composed of magnocellular cells ("M cells"). These cells mark the beginning of the M pathways from the LGN to the striate cortex, providing static, depth and motion information to the striate cortex.
Akinetopsia would, therefore, result from damage to the magnocellular layers of the lateral geniculate nucleus (LGN). Akinetopsia or "motion blindness", is a neuropsychological disorder in which a patient cannot perceive motion in their visual field, despite being able to see stationary objects without issue.
Simultagnosia is a neurological disorder characterized by the inability of an individual to perceive more than a single object at a time. Ventral occipito-temporal lesions may cause a mild form of this rare disorder, while dorsal occipito-parietal lesions cause a more severe form of the disorder.
Achromatopsia is a condition characterised by a partial or total absence of colour vision. The condition also involves other problems with vision, including an increased sensitivity to light and glare (photophobia), involuntary back-and-forth eye movements (nystagmus), and significantly reduced sharpness of vision (low visual acuity). Individuals may have myopia or hyperopia. Achromatopsia may be acquired via cortical damage that arises through ischemia or infarction of the ventral occipitotemporal cortex or it may be congenital due to an autosomal recessive congenital colour vision condition.
Visual apperceptive agnosia is a condition in which a person fails to recognise objects due to a functional impairment of the occipito-temporal vision areas of the brain.
Which of the following statements is most characteristic of rod photoreceptor cells?
C) "They are specialised for light sensitivity at the expense of resolution."
Rods are photoreceptor cells that have a low spatial resolution but are extremely sensitive to light (even as low as a single photon). They are therefore specialised for light sensitivity at the expense of resolution.
Rods are present in the periphery of the retina (90-100mill in total). This explains why the threshold for detecting a light stimulus is lower outside the region of central vision.
All rod photoreceptors contain rhodopsin. Cone photoreceptor cells, on the other hand, differ in the photopigment they contain. The different photopigments have different sensitivity to light of different wavelengths. Individual cones thus provide colour information for the wavelength of light that excites them best; short wavelengths result in the colour blue, medium green and long red.
In left-brain dominant individuals, which area of the brain is most responsible for interpreting the emotional tone of speech?
A) Left posterior section of superior temporal gyrus (Wernicke's area)
Wernicke's area involves the comprehension of written and spoken language. The correct answer here would be Wernicke's area in the dominant hemisphere: the left posterior section of the superior temporal gyrus.
Left-brain dominant individuals use the left side of their brain for the interpretation and production of speech. Therefore, whilst the right posterior section of the superior temporal gyrus (Wernicke's area) could have some involvement in interpreting speech, the left side would be a more appropriate answer.
The frontal lobe, left premotor area (Broca's area) and the frontal lobe, right premotor area (Broca's area) are both incorrect answers. Broca's area is linked to speech production rather than speech interpretation.
The cingulate cortex is considered part of the limbic system and has a role in the formation and processing of emotions. It does not have a role in interpreting the emotional tone of speech and so would not be a correct answer here.
Which region of the brain is commonly associated with the behavioural and physiological responses to fear and threats?
C) Amygdala
The amygdala is associated with fear responses, including both behaviours (snarling, arched backs, growling) and physiological changes (increased heart, breathing rate and blood pressure) in animals and humans.
SM was a female patient who suffered bilateral amygdala destruction and was no longer able to respond appropriately to threatening situations or recognise faces showing fear.
A 65-year-old man presents to A&E with involuntary movements of his left arm. He is subsequently diagnosed with hemiballism.
Which anatomical region is likely damaged in this patient?
B) Subthalamic nucleus
Hemiballism is a very rare movement disorder. It is a type of chorea caused in most cases by a decrease in activity of the subthalamic nucleus of the basal ganglia, resulting in the appearance of flailing, ballistic, undesired movements of the limbs.
The subthalamic nucleus is damaged in hemiballism. This nucleus is located ventral to the thalamus and dorsal to the substantia nigra. When it is damaged there is decreased excitation in the globes pallidus internus and this reduces inhibition of the thalamus thereby resulting in contralateral hemiballism. This can occur in a lacunar stroke.
Damage to the lentiform nucleus can occur in Wilson's disease.
Atrophy of the caudate nucleus occurs in Huntington's disease.
Degeneration of the substantia nigra occurs Parkinson's disease.
Which of the following branistem nuclei are primarily concerned with auditory tone?
C) Dorsal cochlear nuclei
The two dorsal cochlear nuclei (DCN) together with the ventral cochlear nucleus (VCN) comprise the cochlear nucleus located in the pons of the midbrain.
The two DCN, one located on either side of the midline in the pons of the brainstem, are primarily concerned with auditory tone. The DCN receives input from CNVIII and from the VCN stellate cells. Most of the DCNs output neurons project to the contralateral inferior colliculus (IC) with a few passing through the SOC. Principal cells that reside in the DCN have very complex frequency intensity tuning curves, their firing rate may be very rapid in response to a low intensity sound at one frequency and then fall below the spontaneous rate with only a small increment in stimulus frequency or intensity. The firing rate may then increase with another increment in intensity or frequency. These cells are excited by wide band noise, and particularly excited by a noise-notch stimulus directly below the cell's best frequency.
The two VCN are concerned with stimulus intensity. Spherical and globular bushy cells of the VCN receive huge auditory nerve endings that are specialized for high fidelity neural transmission in response to acoustic events.
The vestibular nuclei (VN), residing in both the pons and midbrain, are the cranial nuclei for the vestibular nerve (one of the two branches of the vestibulocochlear nerve (CNVIII)).
The inferior colliculus (IC) comprises the principal midbrain nucleus of the auditory pathway. It receives input from several peripheral brainstem nuclei in the auditory pathway, as well as inputs from various cortical areas. It is involved in the integration and routing of multi-modal sensory perception.
The perception and recognition of objects is mediated by which pathway?
C) The occipito-temporal (ventral) pathway
According to the two-stream hypothesis (Milner and Goodale, 1992) the perception and recognition of objects is mediated by the occipito-temporal (ventral) pathway. It is distinct from the occipto-parietal (dorsal) pathway associated with the processing of an object's spatial location relative to the viewer.
Which of these statements about the perception of visual stimuli is true?
C) Due to lateral inhibition, a patch of retina that is illuminated will inhibit the signals transmitted by adjacent photoreceptors that are not illuminated.
In lateral inhibition, if an area of the retina is illuminated, horizontal cells will inhibit the signals from surrounding areas retina that are not inhibited. This is true and is a mechanism of enhancing contrast the contrast of a visual stimulus.
P (parvocellular) cells are very sensitive to colour and have a small receptive field. Conversely, M (magnocellular) cells have a much large receptive field and are not sensitive to colour.
Photoreceptors depolarise when NOT illuminated, and light will hyperpolarise the photoreceptor.
Which of the following describes a proposed mechanism of neural learning where transmissions along frequently used nerve pathways results in greater efficiency of synaptic transmission?
A) Long-term potentiation
Long-term potentiation refers to the strengthening, and therefore increased efficacy of synapses, as a result of continued activation of a specific neural pathway. The theory underlying this mechanism is 'Hebb's rule' - more colloquially described as 'Neuron's that fire together, wire together'.
Long-term potentiation proposes a mechanism of neural plasticity.
A 56-year-old woman presents to her GP with loss of sensation in her feet. Which cutaneous somatic receptors are responsible for detecting vibration and tactile sensation?
E) Meissner's corpuscles
Meissner's corpuscles are important in the detection of vibration and tactile sensation and are encapsulated between dermal papillae. When someone is reading Braille text, they are relying on Meissner's corpuscles to detect the variations in the surface of the page.
Pacinian corpuscles are rapidly adapting (phasic) receptors that detect gross pressure changes and vibrations in the skin. These corpuscles are especially susceptible to vibrations, which they can sense even centimetres away.
Ruffini corpuscles are a type of slowly adapting mechanoreceptor located between the dermal papillae and the hypodermis.This spindle-shaped receptor is sensitive to skin stretch and contributes to the kinesthetic sense of and control of finger position and movement. In particular, they are at the highest density around the fingernails where they are believed to be useful for monitoring slippage of objects along the surface of the skin, allowing modulation of grip on an object.
Merkel nerve endings are mechanoreceptors, a type of sensory receptor, that are found in the basal epidermis and hair follicles. They are nerve endings and provide information on mechanical pressure, position, and deep static touch features, such as shapes and edges.
A free nerve ending is an unspecialised, afferent nerve fibre ending of a sensory neuron. They function as cutaneous nociceptors and are essentially used to detect pain.
Damage to the arcuate fasciculus results in which form of language deficit?
A) Can understand language and speak fluently but cannot repeat phrases
Lesions of the arcuate fasciculus disconnect Wernicke's and Broca's areas. Wernicke's is required for the understanding of language and damage leads to fluent aphasia (can speak fluently but only gibberish). Broca's area is required for the production of speech and thus damage leads to laboured speech production, though understanding of language is retained.
Conductive aphasia describes an individual who can speak fluently and has an understanding of language but since they cannot connect where they perceive language to where they produce language, they cannot repeat things they hear.
Increased levels of which of the following neurotransmitters does NOT increase arousal?
C) GABA
Arousal and wakefulness are regulated largely by five neurotransmitters: acetylcholine, dopamine, histamine, serotonin and noradrenaline. Higher levels of these neurotransmitters are related to higher levels of arousal.
GABA is an inhibitory neurotransmitter and plays a role in reducing arousal.
Which following correctly describes the pathway of the corticospinal tract?
Images from the superior retinal fields synapse onto which cortical region around the calcarine sulcus?
E) Superior
Images from the superior retinal fields synapse onto the superior cortical region immediately above the calcarine sulcus.
Images from the inferior retinal fields synapse onto the inferior cortical region immediately below the calcarine sulcus.
Visual information that is closer to the macula or fovea is transmitted more distally on the calcarine sulcus.
Visual information that is from the peripheral visual fields is transmitted more proximally on the calcarine sulcus.
The visual information cannot synapse medial to the calcarine sulcus, as this is a potential space filled by the falx cerebri. The tissue lateral to the calcarine sulcus is white matter (axons) connecting the visual cortices to each other and other cortical regions.
Visual information cannot synapse external to the brain.
Which of the following best describes the function of the angular gyrus?
B) To integrate sensory information of different modalities (i.e. tactile, auditory and visual)
The function of the angular gyrus is to integrate sensory information of different modalities such as tactile, auditory and visual information from visual, auditory and somatosensory pathways respectively.
For instance, the angular gyrus contains a neural auditory lexicon of words, syllables and numerical or other symbols in an individual's dominant hemisphere, which can be retrieved by visual inputs. It, therefore, matches up graphemes that we read, with phonemes that we have heard facilitating reading aloud.
Which of the following terms best describes the type of vision that occurs in levels of light at which both rod and cone photoreceptors contribute (e.g. twilight)?
A) Mesopic vision
Mesopic vision occurs in levels of light at which both rods and cones contribute (e.g. twilight). It is a combination of photopic vision and scotopic vision in low, but not quite dark lighting situations.
Scotopic vision is the vision of the eye under low-light levels when only the rods are activated.
Photopic vision is the vision of the eye under well-lit conditions. It allows colour perception, mediated by cone cells, and a significantly higher visual acuity and temporal resolution than available with scotopic vision.
Contrast vision refers to contrast sensitivity. It is the difference in luminance or colour that makes an object (or its representation in an image/display) distinguishable and is not a specific rod or cone-mediated type of vision.
What structures comprise the Papez circuit?
B) Hippocampus, mammillary bodies, anterior thalamic nuclei, cingulate gyrus and entorhinal cortex
The Papez circuit comprises the Hippocampus, mammillary bodies, anterior thalamic nuclei, cingulate gyrus and entorhinal cortex. The Papez circuit is a closed neural circuit that is important for regulation of emotion and memory.
Which of the following breaks down serotonin?
B) Monoamine oxidase
Monoamine oxidase breaks down serotonin (a monoamine). Thus, monoamine oxidase inhibitors can be used to boost the levels of serotonin in the brain, therefore providing an anti-depressant effect.
Acetylcholinesterase breaks down acetylcholine.
Catechol-O-methyltransferase (COMT), along with monoamine oxidase, breaks down dopamine. COMT inhibitors can be used in Parkinson's disease to prevent the breakdown of levodopa.
Diamine oxidase breaks down polyamines such as histamine.
Glutamate decarboxylase breaks down GABA.
Which of the following cells is often malfunctioning in Alzheimer’s disease?
E) Microglia
Microglia are the macrophages of the central nervous system. Microglia may fail to clear away debris in Alzheimer’s, leading to further build-up of beta-amyloid and tau.
Oligodendrocytes provide the myelin sheath to the central nervous system, whereas Schwann cells provide the myelin sheath to the peripheral nervous system.
Radial glia generate neurons, astrocytes and oligodendrocytes during embryogenesis.
Dendrites are not a cell, but rather projections from neurons.
Which of the following arteries supplies the paracentral lobule?
D) Anterior cerebral artery
The anterior cerebral artery runs along the medial surface of the cerebral hemisphere, superior to the corpus callosum, and thus supplies the majority of the medial surface of the brain. As the paracentral lobule is found on the medial surface of the brain, this structure is supplied by the anterior cerebral artery.
The middle cerebral artery runs through the Sylvian (lateral) fissure where it emerges on the lateral surface of the cerebral hemisphere and supplies the majority of the lateral surface of the brain.
The posterior cerebral artery runs posteriorly from the circle of Willis where it supplies the majority of the posterior areas of the cerebral hemisphere including the occipital lobe and the inferior aspect of the temporal lobe. The internal carotid artery supplies the anterior circulation from which the anterior and middle cerebral arteries are derived.
The lenticulostriate arteries are small branches of the middle cerebral arteries which are important in the blood supply to the internal capsule.
Damage to, or compression of which nerve may lead to a hoarse voice and breathing difficulties?
B) Recurrent laryngeal nerve
The recurrent laryngeal nerve (RLN) is a branch of the vagus nerve which exits the skull through the jugular foramen and travels down the neck in the carotid sheath. The RLN leaves the vagus nerve in the thorax around T4 and passes underneath the aortic arch before travelling superiorly back towards the larynx. This change of direction is why it is referred to as 'recurrent'. The RLN then goes on to innervate all the intrinsic muscles of the larynx (apart from cricothyroid). One of the key muscles it supplies is posterior cricoarytenoid, which is responsible for opening the vocal cords and ensuring effective sounds can be produced. Hence, when damage occurs to the nerve, the vocal cords can close or become inefficient, giving the classic symptoms of a hoarse voice and difficulty breathing.
Injury to the RLN may be caused by surgery, trauma or a space-occupying lesion such as a tumour or granulomatous disease. A patient presenting with a history of any of these and a hoarse voice should raise your suspicion of RLN injury.
The hypoglossal nerve innervates muscles of the tongue. Damage to this nerve may result in some dysarthria and speech difficulty but is unlikely to cause a hoarse voice or breathing problems.
The facial nerve innervates the muscles of facial expression, provides parasympathetic supply to many salivary glands and provides taste sensation to the anterior two-thirds of the tongue. Damage to the facial nerve usually results in a Bell's Palsy, which is a unilateral loss of facial muscle function.
The long thoracic nerve supplies serratus anterior muscle. Damage to this nerve results in 'winging of the scapula' which is tested for during the shoulder examination.
The phrenic nerve originates from the 4th cervical nerve innervates the diaphragm and has some other sensory functions. As both left and right phrenic nerves have different origins, it is uncommon to have both damaged. Thus, unilateral paralysis of the diaphragm is the usual result of phrenic nerve damage. Irritation of either phrenic nerve may also cause hiccups.
Which of the following is a type of slow-acting sensory fibre?
A) Aβ
There are several classification systems which differentiate axons based upon their thickness and myelination status. The first system splits both sensory and motor fibres into the letters A, B, and C. There are a number of subdivisions of type A, being Aα, Aβ, Aγ, and Aδ. The other system differentiates motor receptors into α, β, and γ, and the sensory receptors are split into Ia, Ib, II, III and IV.
The subclass of A neurones are heavily myelinated and transport the signals at a much higher speed compared with those which are unmyelinated.
Type Aα fibres can be split into both sensory and motor. They have the largest diameter. The sensory type is a stretch receptor found within muscle spindles. They are rapidly adapting and respond to the change in muscle spindle length as well as velocity changes. Another sensory type is present within the Golgi tendon organs within muscles, and work by responding to changes in the muscle contraction. The motor Aα fibres relate to muscle fibre contraction.
Type Aβ fibres are similar to sensory type Aα fibres, however, they are slowly adapting receptors, which mean they respond to continuous signals. The most notable types of Aβneurone are the Merkel disc receptors and bulbous (Ruffini) corpuscles.
Type Aγ fibres are motor fibres that are involved in the contraction of muscle fibres. They do not directly contract muscle fibres but are associated more with continued contraction of muscle fibres.
Type Aδ fibres are afferent nociceptor fibres. They work to relay acute pain responses, either temperature, mechanical or temperature stimuli. This type of fibre act as the afferent stage of the withdrawal reflex. They relay the information to the dorsal horn of the spinal cord.
What is the name given to the intersection of the coronal and sagittal sutures of the skull?
D) Bregma
The bregma is the point of intersection between the sagittal and coronal sutures.
The glabella is located superior to the nasion between the eyebrows and marks the joining of the two brow ridges.
The inion (or external occipital protuberance) is a prominent boney projection originating from the occipital bone.
The pterion is situated in the temporal fossa and marks the junction between four skull bones (frontal, temporal, parietal and sphenoid bones).
The asterion is located posterior to the ear and signifies the area where three cranial sutures meet (lambdoid, parieto-mastoid and occipito-mastoid sutures).
Which type of nerve fiber is primarily responsible for transmitting initial nociception?
D) Aδ
There are different classifications of axon which differentiate the axons based upon their thickness and myelination status. The first system splits both sensory and motor fibres into the letters A, B, and C. There are a number of subdivisions of type A, being Aα, Aβ, Aγ, and Aδ. The other system differentiates motor receptors into α, β, and γ, and the sensory receptors are split into Ia, Ib, II, III and IV.
The subclass of A neurones are heavily myelinated and transport the signals at a much higher speed compared with those which are unmyelinated.
Type Aα fibres can be split into both sensory and motor. They have the largest diameter. The sensory type is a stretch receptor found within muscle spindles. They are rapidly adapting and responding to the change in muscle spindle length as well as velocity changes. Another sensory type is present within the Golgi tendon organs within muscles, and work by responding to changes in the muscle contraction. The motor Aα fibres relate to muscle fibre contraction.
Type Aβ are similar to type Aα but are slowly adapting receptors, which mean they respond to continuous signals. The most notable types of Aβ neurone are the Merkel disc receptors and Bulbous (Ruffini) corpuscles.
Type Aγ fibres are motor fibres that are involved in the contraction of muscle fibres. They do not directly contract muscle fibres but are associated more with continued contraction of muscle fibres.
Type Aδ are afferent nociceptor fibres. They work to relay acute pain responses, either temperature, mechanical or temperature stimuli. This type of fibre act as the afferent stage of the withdrawal reflexes. They relay the information to the dorsal horn of the spinal cord.
The lenticulostriate arteries are important in the blood supply to the internal capsule. From which artery are the lenticulostriate arteries derived?
D) Middle cerebral artery
The internal capsule is an important point in the pathway of ascending and descending tracts. A significant portion of the internal capsule is supplied by the small lenticulostriate arteries which arise from the middle cerebral artery as it passes through the Sylvian (lateral) fissure.
A 26-year-old man is having treatment with chemotherapy for Hodgkin's lymphoma. During his treatment, he has severe vomiting.
Which location in the brain is responsible for his symptoms?
C) Area postrema
Vomiting after chemotherapy is thought to be due to triggering of the chemoreceptor trigger zone (CTZ) which is located on the dorsal surface of the medulla in a region called the area postrema.
Which structure separates the head of the caudate nucleus from the putamen?
E) Anterior limb of internal capsule
In the transverse section image of the brain, you can see the anterior limb of the internal capsule separating the head of the caudate nucleus from the Globus Pallidus and Putamen.
Which dopaminergic pathway is involved in the regulation and production of movement?
B) Nigrostriatal pathway
Movement regulation and production is initiated in the substantia nigra, which is one of the basal ganglia, and projects into the striatum, which contains the caudate and putamen nuclei, which are also basal ganglia. This pathway is known as the nigrostriatal pathway (nigra à striatum). It works via direct and indirect pathways, of which the direct pathway contains D1 dopamine receptors, and the indirect pathway contains D2 dopamine receptors.
The tuberoinfundibular pathway originates in the arcuate nucleus and projects to the tuberal region of the hypothalamus. The arcuate nucleus is also known as the infundibular nucleus, hence why it is known as the tuberoinfundibular pathway. The exact function of this pathway is not fully understood, but the D2 receptors inhibit the production of prolactin. D2 antagonists can cause hyperprolactinaemia through this pathway.
The connection between the ventral tegmentum and the prefrontal cortex is known as the mesocortical pathway. It is involved in cognition and emotion, and dysfunction of this pathway is thought to be the underlying cause for psychotic disorders such as schizophrenia.
The mesolimbic pathway, which is commonly known as the reward pathway, is a pathway between the ventral tegmental area and the striatum, which is the amalgamation of the caudate and putamen nuclei. This pathway is heavily active in motivation and reinforcement through reward. It is thought that overactivation of this pathway is heavily linked to addiction.
Failure of the neural tube to close in the cephalic region causing subsequent underdevelopment of the cerebral hemispheres is referred to as?
C) Anencephaly
Anencephaly refers to the failed development of large portions of the cerebral hemispheres, meninges, skull and scalp.
It is caused by a failure of the rostral (or cephalic) end of the neural tube to close between days 23rd-26th of foetal development.
Which of the following nerve nuclei may be found anterolateral to the periaqueductal grey matter in the lower midbrain?
B) Trochlear nerve nucleus
The trochlear nerve (CN IV) nucleus may be found anterolateral to the periaqueductal grey matter in the lower midbrain.
The oculomotor nerve (CN III) nucleus lies adjacent to the periaqueductal grey matter, either side anteriorly, in the superior midbrain.
The principal (tactile) nucleus of the huge trigeminal nerve (VN V) nucleus lies in the pons. The proprioceptiveand pain nuclei lie in the midbrain and medulla, respectively.
The abducens nerve (CN VI) nucleus resides in the pons, on the floor of the fourth ventricle, at the level of the facial colliculus.
The sigmoid sinus converges with the inferior petrosal sinus to become what structure at the jugular foramen?
B) Internal jugular vein
The inferior petrosal sinus and the sigmoid sinus join to form the internal jugular vein at the jugular foramen.
Where is the most common location for a subarachnoid haemorrhage?
E) Between posterior communicating and internal carotid artery
Aneurysms form at areas of turbulence. In the largest artery - the internal carotid artery - resistance will be comparably lower to vessels of a smaller radius, such as the posterior communicating artery.
Imagine the internal carotid artery is the northbound half of the M1 motorway when there's no roadworks. It has a large radius (3 lanes) and lots of blood (cars) flowing along at a high speed. Suddenly there is a narrow slip road off the M1 (the posterior communicating artery) where a proportional number of cars will pass through. As it is much narrower, resistance is much greater so the cars/blood pass through more slowly. As you could imagine, overtime there's a few cars accidents at that junction due to the rapid deceleration and change in pressure - i.e. aneurysms commonly form there.
The posterior communicating artery is the first junction off the busy internal carotid artery into the circle of Willis. After this, differences in pressure and turbulence between arteries is less so. However aneurysms may still form elsewhere, especially in hypertensive patients.
The 12 paired cranial nerves (CNs) that emerge from the brainstem control much of the motor and sensory functions of the head and neck. The majority of these CNs exit the brainstem from the ventral (anterior) aspect.
Which of the following CNs is unique as it is the only one that exits from the dorsal (posterior) aspect of the brainstem?
E) Trochlear nerve
The correct answer is the trochlear nerve (CN IV) as it is the only cranial nerve that exits from the dorsal aspect of the brainstem. It is also the smallest nerve in terms of the number of axons it contains but has the greatest intracranial length. The trochlear nerve is a motor nerve that innervates the superior oblique muscle of the eye, which controls rotational movement.
The optic nerve (CN II) exits the brainstem from the ventral aspect and carries visual information from the retina of the eye to the brain.
The vestibulocochlear nerve (CN VIII) exits the brainstem from the ventral aspect and is responsible for transmitting sound and balance information from the inner ear to the brain.
The vagus nerve (CN X) exits the brainstem from the ventral aspect and is responsible for many tasks, including heart rate, gastrointestinal peristalsis, sweating, and muscle movements in the mouth, including speech and keeping the larynx open for breathing.
The abducens nerve (CN VI) exits the brainstem from the ventral aspect is a motor nerve that innervates the lateral rectus muscle of the eye, which controls lateral movement.
What Brodmann area does the primary motor cortex of the brain correspond to?
C) Brodmann area 4
Brodmann area 4 is part of the precentral gyrus and corresponds to the primary motor cortex of the human brain. This is located in the posterior portion of the frontal lobe.
Brodmann area 28, as well as Broadmann area 34, correspond to the entorhinal cortex.
Brodmann area 44 is also known as the pars opercularis, together with Brodmann area 45 comprises "Broca's area".
Brodmann area 11 corresponds to the orbitofrontal cortex and is thought to be involved in decision making.
Which structure connects the fourth ventricle to the subarachnoid space?
D) Foramen of Luschka
The foramen of Luschka is a natural aperture at the cerebellopontine angle between the fourth ventricle and the subarachnoid space.
The foramen of Magendie links the fourth ventricle to the cisterna magna.
The foramen of Monro (interventricular foramen) connects the third ventricle and the lateral ventricles.
The aqueduct of Sylvius (cerebral aqueduct) connects the third ventricle to the fourth ventricle.
Which of the following is not a part of the limbic system?
E) Thalamus
The limbic system is a functional system in the brain that spans many anatomical structures. Because of its functional classification, it is often less talked about in neuroanatomy and left to the neurosciences.
It is important for lower order processing of emotional responses, olfaction (smelling), long-term memory, behaviour, and motivation.
It is found either side of the thalamus and massa intermedia, and can be divided into three distinct anatomical regions:
1. Cortical regions:
a. Orbitofrontal cortex - decision making
b. Hippocampus - memory consolidation and associative emotional control
c. Fornix: axonal tracts connecting the hippocampus to the mammillary bodies and septal nuclei
d. Piriform cortex - a small cortical processor of olfaction
e. Limbic lobe - sensoriemotional integration, memory
f. Entorhinal cortex - memory
2. Subcortical areas:
a. Amygdala - deep in the temporal lobes; emotional integration and association
b. Septal nuclei - a pleasure zone
c. Nucleus accumbens - reward, addiction and pleasure
3. Diencephalic structures:
a. Mammillary bodies - recollective memory (potentially spatial memory)
b. Anterior nuclei of thalamus: receive input from the mammillary bodies and involved in memory processing
c. Hypothalamus - autonomic process regulator (including emotional responses to memories, smell, tactition, hearing and sight)
The thalamus itself is part of the diencephalon, and is a deep nucleus within the brain. It is the gateway for ascending sensory signals and descending motor signals.
Broca's area occupies which of the following cortical locations?
B) Inferior frontal gyrus
Broca's area is a cortical area in the human brain that resides in the inferior frontal gyrus of an individuals dominant hemisphere (usually the left). First discovered by the work of Pierre Paul Broca (1824-1880), the area is associated with speech production. An impairment in this area results in an inability to speak coherently despite a retained ability to understand the spoken and written word.
What cells do the efferent axons of the cerebellar cortex arise from?
C) Purkinje cells
Purkinje cells are the only output cells of the cerebellar cortex. As they are GABAergic, the output of the cerebellar cortex is solely inhibitory. Purkinje cells in turn project to the deep cerebellar nuclei.
What region in the hypothalamus is responsible for controlling circadian rhythms?
A) Suprachiasmatic nucleus
The suprachiasmatic nucleus (SCN) is situated directly above the optic chiasm and is responsible for controlling circadian rhythms.
The anterior hypothalamus nucleus is involved in thermoregulation of the body.
The lateral hypothalamic area is involved in the regulation of wakefulness, appetite and arousal.
The ventromedial nucleus (VMN) is primarily involved in regulating satiety. (It terminates hunger)
You conduct a cranial nerve examination on a patient complaining of drooping of the mouth. On examination, you find that there is drooping of the right corner of the mouth. They are also unable to smile on the right side or raise their right eyebrow.
Where is the lesion most likely to be found?
D) Right peripheral CN VII
The distribution of symptoms suggests a lower 7th cranial nerve palsy on the ipsilateral side to the symptoms, therefore the correct answer is a right peripheral CNVII nerve lesion. This is because both the upper (orbital) and lower (oral) facial muscles have been affected.
A left peripheral CNVII nerve lesion would produce the same symptoms but on the left side of the face.
A left central CNVII nerve lesion causes a “forehead sparing” distribution of symptoms on the contralateral side. It would cause similar symptoms with drooping of the right corner of the mouth and inability to blow out the right cheek, but the patient would be able to raise their right eyebrow.
A right central CNVII nerve lesion would cause a “forehead sparing” distribution again on the contralateral side to the lesion, so it would cause a lower facial muscle weakness on the left side of the face.
These distributions can be explained by looking at the nerve supply to the facial muscles. The upper facial muscles have nerve supply from both sides of the brain, whereas the lower facial muscles only have nerve supply from the contralateral side of the brain.
A central CNVII nerve lesion wipes out the only nerve supply to the contralateral lower facial muscles, but the upper facial muscles still have the ipsilateral nerve supply. This renders the upper facial muscles on the contralateral side to the lesion intact but the lower facial muscles paralysed.
A peripheral CNVII nerve lesion affects the nerve after the nerve supply to the facial muscles has crossed the midline and the bilateral supply to the upper facial muscles have joined. This means the lesion obliterates all nerve supply to the ipsilateral side of the face, causing total hemifacial muscle paralysis.
Which nerve passes through the inner ear but does not innervate any structures?
E) Facial nerve
The facial nerve (CN VII) passes through the inner ear but does not innervate any of its structures.
The vestibulocochlear nerve (CN VIII) is also located in the inner ear and splits into the vestibular nerve, with the superior and inferior branches supplying the utricle, saccule and three semi-circular ducts, and the cochlear nerve, with its branches suppling receptors of the Organ of Corti.
The vagus nerve (CN X) has branches involved in the innervation of external ear structures, specifically, the deeper aspects of the auricle and the external auditory meatus.
The greater auricular nerve, which is a branch of the cervical plexus, innervates the skin of the auricle.
What lies immediately deep to the cranial bone?
C) Dura mater
The dura mater lies immediately deep to the cranium. It is the outermost meningeal layer, which is followed by the arachnoid mater, then pia mater.
A 55-year-old mechanic is sent to general practice by his wife for investigation of a year-long history of worsening left-sided tinnitus and progressive hearing loss. He initially attributed this to loud noise at work but has recently taken on more sales duties and noticed no improvement. On examination the patient can hear a ticking wristwatch in the right ear but not the left. Weber’s test lateralises to the right side.
The GP suspects an acoustic neuroma, and MRI scan reveals a subarachnoid mass growing close to the left cerebellopontine angle. Which of the following structures exits the cranial vault alongside the vestibulocochlear nerve, and is vulnerable to injury if this tumour is excised?
D) Facial nerve
The vestibulocochlear nerve exits the cranial vault via the internal acoustic meatus along with the facial nerve and the labyrinthine artery.
Acoustic neuromas, also known as vestibular schwannomas, are classically slow-growing benign tumours arising from the neurilemmal sheath of the vestibular nerve. They present most commonly in adults aged between 30 and 60 years old, with progressive ipsilateral sensorineural deafness and tinnitus due to compression of cochlear nerve fibres. The compressive effect is such that over time it may even progressively enlarge the internal acoustic meatus.
As the tumours grow in size they may begin to exert pressure on the cerebellum and brainstem within the cerebellopontine angle, resulting in compression of cranial nerve roots V, IX, X and XI. In many instances a surveillance strategy is adopted with regular MRI follow-up; surgery is possible but not always necessary for slow-growing tumours producing few or tolerable effects. Stereotactic radiosurgery is becoming increasingly available for removal of smaller tumours.
Which of the following muscles is not innervated by the inferior division of the oculomotor nerve?
B) Levator palpebrae superioris
The superior division of CN III innervates the superior rectus and levator palpebrae superioris muscles.
The inferior division of CN III supplies the medial and inferior recti, as well as the inferior oblique muscles.This division also sends a parasympathetic autonomic branch to the ciliary ganglion in the orbital cavity, which assists in activating the sphincter pupillae and ciliary muscle.
A 57-year-old female patient presents with pyrexia, shortness of breath and pain to the tip of her shoulder post-thoracic surgery. She is diagnosed with mediastinitis.
Which of the following options best explain this presentation of pain?
A) The phrenic nerve innervates the mediastinal pleura.
The C5 dermatome terminates inferolaterally at the lateral-most tip of the pectoral girdle. The phrenic nerve contains the root value C3, 4, 5. Thus irritation of this nerve can cause referred pain to the C3-5 dermatomes.
The patient has an infection, thus inflammation, of her mediastinum which has irritated the parietal pleura in that region. The parietal pleura is innervated by the phrenic nerve as it passes on the outside of the fibrous layer of the pericardium.
The vagus nerve is not involved in mediastinal pleura sensory supply
The phrenic and intercostal nerves innervate the parietal pleura - thus neither are alone in their supply.
There is no evidence in the stem to suggest more superiorly-placed thoracic infection spread.
Which of the following best describes the distribution of fibres in the cerebral crus (crus cerebri)?
B) The middle three-fifths of each crus contains corticospinal fibres, the medial fifth by frontopontine fibres, the lateral fifth by temporopontine fibres.
The middle three-fifths of each cerebral crus contains corticospinal fibres. The corticospinal pathways descend from the posterior limb of the internal capsule through the middle three-fifths of the cerebral crus on either side on their way down through the pons and midbrain to the spinal cord. Corticonuclear fibres also lie on the most medial side of this bundle, as they will decussate shortly to terminate their cranial nerve nuclei but there are far fewer corticonuclear than corticospinal fibres.
Frontopontine fibres occupy the medial fifth of each crus, they form part of the extrapyramidal pathway.
Temporopontine fibres make up the lateral fifth of each cerebral crus. The exact functions of temporopontine fibres are unknown but given that they terminate in the cerebellum they are almost certainly involved in balance, movement and speech.
Which of the following lie in the tissue deep to the piriform sinus (fossa)?
A) Internal laryngeal nerve
The piriform sinus is the space formed by the aryepiglottic fold medially, and the thyroid cartilage and thyrohyoid membrane laterally.
It is richly innervated by the internal laryngeal nerve, and the recurrent laryngeal nerve can be found in close proximity. It should be noted that the recurrent laryngeal nerve does not supply sensory innervation to this region.
Foreign bodies can become trapped in the piriform sinus and lead to a foreign body sensation or a cough. It is also an important anatomical landmark for the staging of head and neck cancer.
The superior thyroid artery lies superficial to the piriform sinus, and supplies the superior aspect of the thyroid gland; it is not deep to the piriform sinus.
The epiglottis lies superior to the piriform sinus.
The acromion of the scapula is not near this region.
The external laryngeal nerve combines with the internal laryngeal nerve to form the superior laryngeal nerve. However, it does not lie deep to the piriform sinus, instead travelling inferolateral to the internal laryngeal nerve to supply motor innervation to the cricothyroid muscle.
Broca's and Wernicke's area are considered to be the two main language areas of the human cortex. Which white matter tract connects them?
B) Arcuate fasciculus
Broca's and Wernicke's areas are connected via the arcuate fasciculus. Damage to this tract results in conduction aphasia, in which the patient cannot repeat unfamiliar words or sounds, and finds it difficult to learn new words.
The medial longitudinal fasciculus is located in the midbrain and is responsible for the coordination of eye movements via cranial nerves III, IV, and VI.
The medial leminiscus is part of the dorsal column sensory tract.
The superior longitudinal fasciculus is a major association tract in the brain that is comprised of 3 separate components. Anatomically, the arcuate fasciculus can be considered a subdivision of the superior longitudinal fasciculus.
Which two arteries initially supply the Circle of Willis?
D) Internal carotid arteries and vertebral arteries
The Circle of Willis is supplied by the 2 vertebral arteries and the 2 internal carotid arteries.
The internal carotids form at the bifurcation of the common carotid. The internal carotids go on to form the anterior and middle cerebral arteries, whilst the external carotids supply the face and anterior neck. The vertebral arteries arise from the subclavian arteries, before converging to form the single basilar artery at the base of the Circle of Willis.
Arnold's nerve is a branch of which cranial nerve?
C) Vagus nerve
The auricular branch of the vagus nerve is often termed the Alderman's nerve or Arnold's nerve. This branch of the vagus nerve supplies sensory innervation to the skin of the ear canal, tragus, and auricle.
The occlusion of this artery classically results to total anterior circulation stroke (TACS).
A) Middle cerebral artery
Meanwhile, occlusion of the anterior cerebral artery commonly results to partial anterior circulation stroke (PACS), but may also result to TACS.
Which of the following structures would be considered part of the diencephalon?
B) Pineal gland
The pineal gland is located in the region of the epithalamus, close to the third ventricle, and as a result is embryologically considered part of the diencephalon. It secretes melatonin, and thus plays an important role in sleep.
The substantia nigra and superior colliculus are both located within the midbrain, and are thus considered part of the mesencephalon.
The olfactory bulb and amygdala are both cortical regions, although both are evolutionarily much older than the neocortex. Consequently they are considered part of the telencephalon.
In the pupillary light reflex, which nucleus acts as the beginning of the efferent pathway?
The oculomotor nerve transmits the impulse from the Edinger-Westphal nucleus to the ciliary ganglion, where it synapses with the short ciliary nerves, which innervate the pupillary sphincter.
A 55-year-old woman presented to the emergency department complaining of a headache and double vision. She had been experiencing an aching right-sided headache and a droopy eyelid for two weeks and double vision for the last 3 days. On examination, she is found to have right-sided ptosis, mydriasis with a sluggish light reflex and inferior-lateral deviation of the right eye. There are no other neurological deficits noted on examination.
Which nerve is MOST likely affected?
E) Oculomotor nerve
The oculomotor nerve is involved in the movement of the eye, raising of the eyelid, pupillary constriction and accommodation. Palsy can be caused by a posterior communicating artery aneurysm, raised intracranial pressure, cavernous sinus thrombosis and uncal herniation.
Which cranial nerve ganglion is located in Meckel’s Cave?
B) Trigeminal nerve
The trigeminal ganglion is located in Meckel’s Cave within the temporal bone, lateral to the cavernous sinus.
Which of the following describes the role of the subthalamus in the indirect pathway of the basal ganglia?
E) Indirect thalamic inhibition via excitation of globus pallidus interna
The subthalamus achieves indirect thalamic inhibition via excitation of globus pallidus interna. This results in reduction of movement by reduced excitation of the cortex.
Which layer of meninges forms the falx cerebri and the tentorium cerebelli?
C) Dura mater
The dura mater is strong, dense outermost layer of the three layers of dura, made of fibrous tissue. The falx cerebri and the tentorium cerebelli are strong dense layers of the dura. The falx separates the two hemispheres of the brain and the tentorium separates the cerebrum superiorly from the cerebellum inferiorly.
There are three layers of meninges:
1. Dura mater - thick, fibrous, outermost layer
2. Arachnoid mater - thin, fibrous layer, is a delicate network impermeable to fluid that allows expansion
3. Pia mater - thin, innermost layer of meninges that is also impermeable to fluid
The galea aponeurosis is a layer of the scalp and not one of the layers of the meninges.
What meningeal fold extends into the longitudinal fissure from above?
B) Falx cerebri
The falx cerebri extends into the longitudinal fissure from above, preventing torsional (twisting) forces from damaging the hemispheres.
It is a large, crescent-shaped fold of meningeal layer of dura mater that descends vertically in the longitudinal fissure between the cerebral hemispheres of the human brain. The falx cerebri attaches anteriorly at the crista galli in proximity to the cribriform plate and to the frontal and ethmoid sinuses. Posteriorly, it is connected to the upper surface of the cerebellar tentorium.
The cell types in the human nervous system can be broadly split into neurons and glial cells. Which of the following glial cells has a major role in the formation of the blood-brain barrier?
A) Astrocytes
The perivascular endfeet of the astrocytes surround the abluminal surface of the capillaries and are involved in the secretion or absorption of neural transmitters and maintenance of the blood-brain barrier.
Ependymal cells have a role in forming the choroid plexus.
Oligodendrocytes have a role in myelination of neurons in the central nervous system (as opposed to Schwann cells which have a similar function but in the peripheral nervous system).
Microglia originate from monocytes in the bloodstream and form phagocytes used in immune defense.
Satellite cells cover the surface of neuron cell bodies in ganglia of the peripheral nervous system.
The middle cerebral artery typically bifurcates as it passes over which structure?
A) Limen insulae
The middle cerebral artery (MCA) most often bifurcates as it passes over the Limen insulae. Following bifurcation, the M2 branches pass over the surface of the insula. These then make a hairpin turn downwards as the M3 segments, passing along the medial surface of the operculum. As the MCA passes out of the Sylvian fissure and onto the cortical surface it forms the M4 or cortical segments.
Which of the following is NOT a branch of the internal carotid artery?
C) Anterior communicating artery
The anterior communicating artery is a branch of the anterior cerebral arteries, not the internal carotid.
The ophthalmic and superior hypophyseal arteries are given off from the ophthalmic (C6) segment of the internal carotid artery.
The anterior cerebral artery and posterior communicating artery are given off from the communicating (C7) segment of the internal carotid artery.
Which of the following supplies the pineal gland?
C) Posterior choroidal arteries
The posterior choroidal arteries supply the pineal gland. These arise from the posterior cerebral artery.
Which of the following dermatomal nerve root pairings is incorrect?
D) L2 - genitalia
The genitalia are supplied by spinal roots S2 and S3. Sensory neuronal cell bodies are found in the dorsal root ganglia. There is often some variation in the dermatomal mapping patterns depending on the methods used to construct them. On the whole, most areas of skin are innervated by 2 spinal nerve roots.
Other classic dermatomes most frequently asked about include:
T10 (umbilicus)
T4 (nipples)
L4 (medial malleolus)
L5 (great toe)
S1 (lateral malleolus)
Which type of neuroreceptor are heavily involved in the formation of memory?
A) NMDA receptor
Long term memory development occurs through long term potentiation, which is the process of increasing the efficiency of a synapse through the repeated activity of that particular synapse. It occurs through the excitatory action of glutamate binding to NMDA receptors. By binding to the NMDA receptors, glutamate removes the Mg2+ ion from the channel, allowing Ca2+ ions to enter the cell and initiate genetic transcription factors to create more AMPA receptors. By creating more ion channels, the neurone has a greater chance of being excited the next time the synapse is activated.
AMPA receptors are a class of glutamate receptor that allows synaptic transmission. They are widespread across the brain, being the most commonly found neuroreceptor. They have a wide range of functions. Whilst they are the primary receptor-activated in the recall of a memory, they are not involved in the formation of memory.
Kainate receptors are another type glutamate receptor which have been found to be involved in both excitatory and inhibitory neurotransmission. Their function is not fully understood, but they have been shown to be involved in neurological diseases such as schizophrenia, autism, and epilepsy.
GABA (gamma-aminobutyric acid) is an important inhibitory neurotransmitter which binds to GABA receptors. GABA receptorsallow the movement of chloride or potassium ions across the cellmembrane. Drugs such as barbiturates and benzodiazepines work by enhancing GABA at these receptors.
Serotonin is a neurotransmitter with a wide array of functions, most commonly associated with the feeling of reward and happiness. 5HT3 receptors are a subtype of serotonin receptors which are permeable to sodium, potassium and calcium ions. They are present in the central and peripheral nervous systems including the nausea and vomiting centre. Medications such as ondansetron target the central 5HT3 receptors to combat nausea and vomiting.
A posterior communicating artery aneurysm is most likely to cause a palsy of which cranial nerve?
C) CN III
CN III, the oculomotor nerve, is the correct answer because the posterior communicating artery passes through the interpeduncular fossa where CN III exits. Ruptured posterior communicating artery aneurysms most commonly present with classic subarachnoid haemorrhage symptoms (sudden onset severe headache, neck stiffness). A complete oculomotor nerve palsy will result in a characteristic down and out position in the affected eye, with associated partial ptosis and mydriasis (dilated pupil).
Which nerve supplies parasympathetic innervation to the lacrimal gland?
B) Facial nerve
The facial nerve supplies the lacrimal gland via the greater petrosal nerve, which synapses at the pterygopalatine ganglion.
Which of the following nerves is responsible for taste in the anterior two-thirds of the tongue?
C) Chorda tympani branch of facial nerve
The chorda tympani nerve is a branch of the facial nerve (cranial nerve VII). It is one of the four intracranial branches of the facial nerve. The facial nerve originates from the pons of the brainstem and contains mainly special sensory (taste) and motor fibres.
The sensation of 'taste' on the tongue is classically split into two anatomical divisions: the anterior two-thirds (anterior to the vallate papillae) and the posterior one-third (posterior to the vallate papillae). The anterior portion is supplied by the chorda tympani (a branch of cranial nerve VII) and the posterior section is supplied by the glossopharyngeal nerve (cranial nerve IX).
The other options are incorrect for the following reasons:
1. Glossopharyngeal nerve - supplies taste to the posterior one-third of the tongue.
2. Vagus nerve - a branch of the vagus nerve (superior laryngeal nerve) has been shown to supply taste to the base of the tongue, but not the anterior two-thirds. The superior laryngeal nerve contains primarily motor and cutaneous sensory fibres to the larynx.
3. Mandibular branch of the trigeminal nerve - the trigeminal nerve is cranial nerve V and the mandibular branch is the third main branch of this nerve (also known as V3). This branch has both sensory and cutaneous innervation but not for taste.
4. Mandibular branch of facial nerve - this is an extracranial branch of the facial nerve which arises when the facial nerve passes between the deep and superficial layers of the parotid gland. This branch contains autonomous fibres to the salivary glands as well as motor innervation for the lower facial muscles (e.g. orbicularis oris).
Between what layers of the meninges is cerebrospinal fluid (CSF) located?
B) Arachnoid mater and pia mater
CSF is located in the subarachnoid space between the arachnoid mater and pia mater.
Which of the following statements best describes the composition of the midbrain?
D) The midbrain comprises the two cerebral crura anteriorly, the tegmentum in the middle and the tectum posteriorly.
The midbrain is the most rostral (uppermost) part of the brainstem. It comprises the two cerebral crura anteriorly, the tegmentum in the middle and the tectum posteriorly. These structures encompass the central connection between the brain and spinal cord.
The pons consists of an anterior basilar part, and posterior tegmentum.
The 4th ventricle communicates inferiorly with which of the following?
A) Central canal of medulla oblongata
The 4th ventricle is a tent-shaped space between the pons and medulla anteriorly, and the cerebellum posteriorly. It communicates inferiorly with the central canal of the medulla oblongata and superiorly with the aqueduct of Sylvius.
Which of the following statements most accurately describes the anatomical location of the pons?
D) The pons lies anterior to the cerebellum.
The pons lies anterior to the cerebellum. The midbrain lies immediately above the pons and the medulla oblongata lies below the pons.
Dopamine is produced from which of the following areas in the midbrain?
C) Substantia nigra pars compacta
The substantia nigra pars compacta produces the dopamine that facilitates fine movement. Dopamine deficiency occurs in Parkinson's disease, resulting in bradykinesia, tremor and postural instability.
The substantia nigra pars reticulata produces GABA, an inhibitory neurotransmitter.
The periaqueductal grey (PAG) is the primary control centre for descending pain modulation. It has enkephalin-producing cells that suppress pain.
The red nucleus is a structure in the rostral midbrain involved in motor coordination. Similar to the substantia nigra it is a subcortical centre of the extrapyramidal motor system but it does not produce dopamine.
Which is the primary neurotransmitter involved in the reward pathway?
E) Dopamine
The mesolimbic pathway, which is commonly known as the reward pathway, is a dopaminergic pathway between the ventral tegmental area and the striatum, which is the amalgamation of the caudate and putamen nuclei, which are basal ganglia. Dopamine is a monoamine neurotransmitter which functions as a neurotransmitter and a hormone. Dopamine is also used between the basal ganglia to regulate motor control. Drugs such as amphetamines and nicotine work by increasing dopamine levels, suggesting that dopamine also has a role in addiction.
Noradrenaline is both a neurotransmitter and a hormone, which acts to initiate the “flight or fight” response. In the brain, it is created in the locus coeruleus in the pons to increase arousal, alertness and it can enhance the formation and retrieval of memory.
GABA (gamma-aminobutyric acid) is an important inhibitory neurotransmitter, bringing about the depression of neuronal excitability. Drugs such and benzodiazepines and alcohol bring about neurodepression through enhancing the action of GABA.
The primary function of acetylcholine is as a neurotransmitter at the neuromuscular junction, although it also acts within the sympathetic and parasympathetic nervous systems. Finally, acetylcholine acts within the brain and is involved with motivation and attention.
Glutamate is one of the primary neuroexcitatory transmitters, which is transmitted between cortical areas as well as the cortex to subcortical regions. It is the most comprehensive excitatory neurotransmitter, making up over 90% of excitatory synaptic connections. It is a major component of synaptic plasticity, which means it is involved with memory and learning.
Which region of the parietal lobe allows for a response to the shape, size, and orientation of objects for grasping and utilization?
C) Anterior intraparietal region
The parietal lobe is subdivided into four regions:
1. The lateral intraparietal region represents spatial locations and identifying triggers for these spaces.
2. The ventral intraparietal region receives audiovisual, somatosensory and vestibular input.
3. The medial intraparietal region plays a role in reaching for targets in reference to the midline.
4. The anterior intraparietal region allows for a response to the shape, size, and orientation of objects for grasping and utilisation.
According to the Kellie-Monro Doctrine, what is the ratio of cerebrospinal fluid, brain and blood, respectively?
B) 10 : 80 :10
According to the Kellie-Monro Doctrine the ratio of cerebrospinal fluid (CSF), brain and blood should be approximately 10:80:10 respectively in a healthy brain. This ratio can change in the context of a space-occupying lesion, cerebral haemorrhage or CSF flow obstruction.
What is the primary function of the basal ganglia?
E) Control of posture and movement
The basal ganglia are a collection of subcortical nuclear masses that lie within each hemisphere. They are grouped together due to their communication and neuronal connections to facilitate control of posture and movement.
The basal ganglia are made up of the caudate nucleus, putamen (the caudate and putamen are often collectively known as the striatum), globus pallidus, substantia nigra and subthalamic nucleus. Through their connections, they facilitate planned and intentional movement via the “direct pathway” and inhibit unwanted movement via the “indirect pathway”.
Planning of movement and decision making is conducted in the motor cortical areas, namely the primary motor cortex, supplementary motor cortex and premotor cortex, all of which are located in the frontal lobe.
The limbic system is responsible for both emotion and feeling as well as memory and learning. The limbic system is bilateral and contains both cortical areas as well as subcortical structures such as the amygdala and nucleus accumbens. It is a complicated system which communicates with a number of other structures and is not fully understood.
Autoregulation is often a process which is governed by peripheral receptors, such as the carotid baroreceptors, however, processes such as regulation of the heart rate and breathing are conducted within the brainstem, with the majority of these functions being controlled by the medulla oblongata.
The pontine arteries are branches of which of the following arteries?
C) Basilar artery
The pontine arteries are small vessels which arise from the basilar artery as part of the posterior circulation. The basilar artery runs along the ventral surface of the brainstem where it gives off the anterior inferior cerebellar arteries, pontine arteries, superior cerebellar arteries and posterior cerebral arteries.
What is the innervation of the efferent limb of the jaw jerk reflex?
D) Trigeminal nerve
The efferent limb of the jaw jerk reflex, which is also known as the masseter reflex,is innervated by the trigeminal nerve (CN V).
The afferent limb of the jaw jerk reflex is also innervated by the trigeminal nerve (CN V)
A patient is diagnosed with homonymous inferior quadrantanopia after a visual field test. Which of the following would be the most likely cause?
D) Parietal lobe tumor
Homonymous inferior quadrantanopia refers to a loss of the inferior quadrant of the left or right visual fields. This is most commonly caused by damage to Baum's loop (superior optic radiation) which conveys information from the thalamus regarding the inferior quadrants of the visual field to the occipital lobe. A parietal lobe tumor would therefore be most associated with this pattern of visual loss, as Baum's loop is located within the parietal lobe.
Temporal lobe tumors may damage Meyer's loop (inferior optic radiation), which would present as homonymous superior quadrantanopia or 'pie in the sky' pattern of visual loss.
Thalamic tumors may damage the lateral geniculate nucleus, but this would cause homonymous hemianopia.
Pituitary tumors are commonly associated with bitemporal hemianopia due to to compression of the optic chiasm in which the temporal fibres from the retinas decussate.
The vertebral arteries arise from which of the following vessels?
C) Subclavian arteries
The vertebral arteries give rise to the anterior spinal artery, posterior inferior cerebellar arteries and the basilar artery. They arise from the subclavian arteries and run in the transverse foramen of the cervical vertebrae before entering the posterior cranial fossa through the foramen magnum.
The common carotid arteries give rise to the internal and external carotid arteries.
The external carotid arteries give rise to a number of vessels that supply the face, head and neck.
The arch of the aorta gives rise to the brachiocephalic, left common carotid and left subclavian arteries.
The axillary artery gives a number of branches to the upper limb including the brachial artery.
Which cranial nerve is most likely to be affected by raised intracranial pressure?
A) Abducens nerve
The abducens nerve has the longest intracranial course and is therefore particularly sensitive to raised intracranial pressure. In the context of raised intracranial pressure, the nerve becomes stretched and an abducens nerve palsy develops, causing the ipsilateral eye to turns in inwards, toward the nose, due to unopposed action of medial rectus.
`You are fortunate enough to observe a rather rare posterior inferior cerebellar artery (PICA) aneurysm being clipped in theatre. At one point early on in the procedure, whilst waiting for one of the nurses to adjust the diathermy current, the neurosurgeon decides to ask you a question.
Of which artery is the PICA most commonly a branch?
E) Vertebral artery
The paired vertebral arteries ascend in the transverse foramina of the cervical vertebrae, giving off the paired posterior inferior cerebellar arteries (PICA). PICA typically supplies the posteroinferior cerebellar hemispheres (including the tonsils), as well as the inferior cerebellar peduncles and inferior vermis.
The vertebral arteries then give off paired branches that unite to form the anterior spinal artery, crucial for perfusion of the anterior two-thirds of the spinal cord (including the descending motor corticospinal tracts, ascending nociceptive spinothalamic tracts and autonomic fibres), which descends in the anterior median fissure: the deep groove visible on the anterior surface of the spinal cord.
The union of the vertebral arteries at the base of the pons forms the single basilar artery, which ascends prominently in a midline depression on the pontine surface, giving off first the paired anterior inferior cerebellar arteries (AICA), and then multiple small pontine branches on either side.
Near its termination, the basilar artery gives off the paired superior cerebellar arteries (SCA), before terminating as the two posterior cerebral arteries (PCA). The posterior communicating arteries (PCoA), by anastomosing with both the posterior cerebral arteries and with the internal carotid arteries, form the bridge between the posterior and anterior circulations.
Inside the cerebral hemispheres, fibres emerge from the cerebral cortex via which of the following structures?
D) Corona radiata
Within the cerebral hemispheres, fibres emerge from, and converge on, the cerebral cortex in the fan-shaped corona radiata. The corona radiata is the white matter sheet that carries most of the neural traffic from and to the cerebral cortex.
The internal capsule is the condensed boomerang-shaped ventral potion of the corona radiata.
The corpus callosum is the large sheet of white matter that connects the two cerebral hemispheres.
The falx cerebri is a meningeal (dural) fold which prevents torsional forces from damaging the hemispheres.
Which of the following best describes folds of the cerebral cortex that overlie the insula?
D) Opercula
Folds of the cerebral cortex overlying the insula are called the opercula. Specifically, the fornix is covered by the frontal, temporal and parietal operculum.
The pallia are the layers of grey and white matter that cover the upper surface of the cerebrum.
The psalterium (or 'lyra') is the thin triangular lamina that joins the lateral portions of the body of the fornix.
Temporal folds refer to folds of cerebrum in the temporal lobe.
The ______________ help(s) to tether the spinal cord within the subarachnoid space, and can often be identified in MRI axial images in the cervical region.
A) Denticulate ligaments
The denticulate ligaments, also known as dentate ligaments, are bilateral triangular lateral extensions of pia mater that anchor the spinal cord to the dura mater. There are normally 21 pairs (18-24). They are formed by pia mater of the spinal cord coursing in between the dorsal and ventral nerve roots bilaterally. They function to provide stability to the spinal cord within the vertebral canal.
The denticulate ligaments are visible on MRI, especially in the cervical region.
The other options are incorrect as follows:
1. The interspinous (interspinal) ligaments are thin and membranous ligaments that connect adjoining spinous processes of the vertebra in the spine. They extend from the root to the apex of each spinous process. They meet the ligamenta flava in front and blend with the supraspinous ligament behind.
2. The posterior longitudinal ligament is situated within the vertebral canal and extends along the posterior surfaces of the bodies of the vertebrae, from the body of the axis, where it is continuous with the tectorial membrane of the atlantoaxial joint, to the sacrum.
3. The ligamenta flava are ligaments of the spine. They connect the laminae of adjacent vertebrae, all the way from the second vertebra, axis, to the first segment of the sacrum. They are best seen from the interior of the vertebral canal; when looked at from the outer surface they appear short, being overlapped by the lamina of the vertebral arch.
Melatonin shares the same precursor (tryptophan) with which other neurotransmitter?
C) Serotonin
Tryptophan is an amino acid which is the precursor for both melatonin and serotonin. Serotonin itself is actually a precursor for melatonin, for which serotonin is acetylated and methylated. Melatonin has a wide range of actions and its actions including the circadian rhythm and is secreted by the pineal gland. Serotonin, on the other hand, is a neurotransmitter related to happiness and the feeling of reward.
Dopamine is an important neurotransmitter for numerous pathways including those related to reward, movement control and emotion. Drugs such as amphetamines and nicotine work by increasing dopamine levels, suggesting that dopamine also has a role in addiction.
GABA (gamma-aminobutyric acid) is an important inhibitory neurotransmitter, bringing about the depression of neuronal excitability. Drugs such and benzodiazepines and alcohol bring about neurodepression through enhancing the action of GABA.
The primary function of acetylcholine is as a neurotransmitter at the neuromuscular junction, although it also acts within the sympathetic and parasympathetic nervous systems. Finally, acetylcholine acts within the brain and is involved with motivation and attention.
Glutamate is one of the primary neuroexcitatory transmitters, which is transmitted between cortical areas as well as the cortex to subcortical regions. It is the most comprehensive excitatory neurotransmitter, making up over 90% of excitatory synaptic connections. It is a major component of synaptic plasticity, which means it is involved with memory and learning.
Which of the following structures is part of the anterior wall of the third ventricle?
D) Lamina terminalis
The anterior wall of the third ventricle comprises the anterior column of the fornix, the anterior commissure and lamina terminalis.
The pineal gland and posterior commissure are both found in the posterior wall of the third ventricle while the optic chiasma is found in the floor of the third ventricle.
The deep structures of the brain, which can be best seen in the coronal section, are separated from each other by distinct white matter tracts. Which of the following white matter structures separate the claustrum from the putamen?
C) External capsule
The extreme capsule separates the insula from the claustrum.
The internal capsule separates the caudate nucleus and the thalamus from the putamen and the globus pallidus.
The medial medullary lamina separates the lateral segment of globus pallidus from the medial segment of globus pallidus.
The lateral medullary lamina separates the putamen from the globus pallidus.
The corpus callosum (indicated by the yellow arrow) is a large, C-shaped nerve fibre bundle found beneath the cerebral cortex. It stretches across the midline of the brain, connecting the left and right cerebral hemispheres, and makes up the largest collection of white matter tissue found in the brain. Which of the following is not a part of the corpus callosum?
E) Fornix
The correct answer is the fornix, as this is the major output tract of the hippocampus, and therefore not part of the corpus callosum. It runs inferiorly to the body of the corpus callosum.
The rostrum is continuous with the lamina terminalis and connects the orbital surfaces of the frontal lobes.
The genu is the most anterior bend of the corpus callosum and the forceps minor is a tract that projects fibres from the genu to connect the medial and lateral surfaces of the frontal lobes.
The body forms the long central section and its fibres pass through the corona radiata to reach the surface of the hemispheres.
The splenium is most posterior, and tapers away at the posterior section, with the forceps major projecting fibres from the splenium to connect the two occipital lobes.
Which part of the thalamus is involved in the Papez circuit?
A) Anterior thalamic nucleus
The main components of the limbic system are made up of the Papez circuit.
The Papez circuit starts at the hippocampus which gives efferent fibres which form the fornix. The fornix is a c-shaped tract which runs along the inferior surface of the anterior horn of the lateral ventricles and downwards forming the anterior border of the interventricular foramen as the column of the fornix and terminates at the mammillary bodies.
The mammillary bodies projects fibres to the anterior nucleus of the thalamus as the mammillothalamic tract.
The anterior thalamic nucleus projects fibres to the cingulate gyrus.
Which of the following is the MOST common site of aneurysmal subarachnoid haemorrhage?
C) Anterior communicating artery
Subarachnoid haemorrhage (SAH) involves bleeding into the subarachnoid space (the area between the arachnoid membrane and the pia mater surrounding the brain). The anterior communicating arteries are the most common site of aneurysmal SAH (34%). They tend to be clinically silent prior to rupture and are therefore rarely detected before an event.
Symptoms of SAH
Severe headache of rapid onset
Vomiting
Decreased level of consciousness
Fever
Seizures.
Neck stiffness
Causes
SAH may occur as a result of a head injury or spontaneously, usually from a ruptured cerebral aneurysm.
Most cases of SAH are due to trauma
Spontaneous SAH is usually due to rupture of a cerebral aneurysm (85%)
Which of the following symptoms would you NOT expect from damage to cranial nerve VII (facial) at the level of the internal acoustic meatus?
A) Loss of jaw jerk reflex
Cranial nerve VII (facial nerve) has a particularly tortuous journey upon leaving the brain. It enters the internal acoustic meatus and travels within the wall of the middle ear before leaving the skull via the stylomastoid foramen. Prior to leaving the skull, it gives off 3 important branches - chorda tympani, nerve to stapedius and the greater petrosal nerve.
Loss of jaw jerk reflex is the correct answer because cranial nerve V (trigeminal) is the only nerve that contributes to this arc.
Dry eyes and mouth would be expected because the greater petrosal nerve contains the pre-ganglionic parasympathetic supply to the lacrimal gland, which is responsible for the production of tears and hydration of the eye. Likewise, chorda tympani contains pre-ganglionic fibres that will eventually synapse with post-ganglionic fibres supplying the submandibular and sublingual salivary glands.
Hyperacusis would be expected because the nerve to stapedius (as the name suggests) innervates the stapedius muscle in the inner ear which helps to protect the conductive apparatus from excessive noise.
Reduced taste sensation would be expected because chorda tympani innervates the tongue and is responsible for gustatory sensation (as well as somatosensation) from the anterior 2/3rds of the tongue
Complete facial hemiparesis would be expected because the primary function of cranial nerve VII is to innervate the ipsilateral muscles of facial expression. The term 'complete' refers to the fact that upper motor neuron injuries (e.g. stroke) cause forehead-sparing facial hemiparesis, whilst lower motor neuron injuries (as in this example) do not spare the forehead.
Which layer of the primary motor cortex contains the Betz cells?
B) Layer V (internal pyramidal)
The cortex of any part of the brain can be divided into six layers, each of which can be differentiated due to their varying connections with other regions of the brain.
Within the primary motor cortex, the pyramidal Betz cells are located within the 5th layer (layer V) of the cortex. Betz cells are particularly important as they are the upper motor neurones which have very long axons that descend down the spinal cord in the corticospinal tract and synapse with the lower motor neurones to stimulate muscle contraction.
The full list of cerebral cortex layers are as follows:
Layer I – Molecular layer
Layer II – External granular layer
Layer III – External pyramidal layer
Layer IV – Internal granular layer
Layer V – Internal pyramidal layer
Layer VI – Multiform layer
Which of the following foramen is an often site of obstruction secondary to neoplasms?
A) Aqueduct of Sylvius
Which of the following cranial nerves is most likely to be injured by a tumour in the interpeduncular fossa?
A) Oculomotor nerve
Cranial nerve III exits the midbrain within the interpeduncular fossa, the space between the left and right cerebral peduncles that make up the ventral surface of the midbrain. As a result, a tumour in this area could compress either of the paired nerves.
Cranial nerve IV exits the midbrain on the dorsal surface of the midbrain, and thus does not run near the interpeduncular fossa.
Cranial nerves V, VI, and VII all exit from the pons, and thus do not run near the interpeduncular fossa.
What is the function of the dorsolateral prefrontal cortex (DLPFC)?
D) Behaviour planning and organisation in pursuit of short, medium and long-term goals
Located on the dorsal (which at the level of the cortex means superior) and lateral aspect of the frontal lobe anterior to the primary motor cortex.
The dorsolateral prefrontal cortex is responsible for behaviour planning and organisation in pursuit of short, medium and long-term goals.
A lesion to what structure in the brain would produce truncal ataxia and dysarthria?
B) Cerebellar vermis
Lesions to the midline structures of the cerebellum such as the vermis would classically produce truncal ataxia (which would present as a wide-based gait) and dysarthria.
A lesion to the cerebellar hemispheres (which are located laterally) can present with intention tremor, dysdiadochokinesia (inability to perform rapid alternating movements), loss of balance, dysmetria (inability to judge distances) and rebound phenomena.
Which cells in the brain are responsible for lining the ventricles and directing cell migration during development?
B) Ependymal cells
Ependymal cells are ciliated simple columnar cells which line the ventricles of the brain.
Which one of the following cranial nerve nuclei is ONLY contralaterally innervated by the primary motor cortex?
C) CN XII
The hypoglossal nucleus is a collection of motor neuron bodies situated in the dorsal medulla oblongata. It can be seen lying on the floor of the fourth ventricle as the hypoglossal trigone.
The hypoglossal nucleus sends efferent fibres ventrolaterally through the medulla to emerge from the pre-olivary sulcus. It is the only nucleus to emerge before the inferior olive – CNs IX, X and XI emerge behind it.
The hypoglossal nucleus only receives input from the contralateral motor cortex. Therefore, if there is an upper motor neuron lesion, the tongue deviates away from the lesion, however, if there is a lower motor neuron lesion, the tongue deviates towards the lesion.
