-
The trigger zone of a neuron includes
the dendrites
-
at the distal end of a nerve fiber, action potentials have the same voltage as they had at thte beginning. That is to say they are
nondecremental
-
when a neuron is depolarized to threshold,
voltage-regulated Na+ gates open
-
the falling phase of an action potential results from
the diffusion of K+
-
nerve signals,
travel fastest in large myelinated fibers
-
One role of the astrocytes is to
help the blood brain barrier
-
what is an example of an effector
an efferent neuron
-
the intergrative function of the nervous system is associated especially with
association neurons (interneurons)
-
The ____ nervous system carries brain and spinal cord signals to other organs
central
-
a neuron fires only when its membrane reaches
the threshold potential
-
During the rising phase of an action potential
Na+ is entering the neuron
-
The cytoplasm, nucleus, and outer wrapping of plasma mambrane of the schwann cells constitute the
myelin
-
The first thing that occurs when a nerve signal reaches a synaptic knob is
ACh binds to a receptor
-
A bipolar neuron has
one axon and one dendrite arising from the soma
-
The regeneration tube of a peripheral nerve fiber consist of
the myelin sheath and neurolemma
-
Mature neurons lack centrioles. You would expect these neurons to be unable to
undergo mitosis
-
The oligodendrocyte is found in the ___ and functions to
central nervous system, form the myelin sheath
-
Glial cells which resemble a cubiotal epithelium without the basement membrane and produce CSF are called
ependymal cells
-
Most adult brain tumors are composed of___ cells and cannot be treated by chemotherapy because of the _____.
glial cells; blood brain barrier
-
neurons that send impulses to skeletal muscles have a ____ diameter and are___
large; myelinated
-
What is the correct sequence of voltage-regulated gates opening and closing in an action potential?
Na+ gates opening; K+ gates opening; Na+ gates closing
-
the ventral rami of the spinal nerves from nerves plexuses in all regions except
the thoracic region
-
The spinal cord ends at about which vertebrae?
L1
-
Nerves in the pelvic region and lower limbs arise from an area of the spinal cord called the ____ enlargement
lumbar
-
A bundle of nerve roots that occupy the canal of the vertebrae L2 to S5 are called the
cauda equina
-
Spinal cord injuries commonly result from fractures of vertebraes C5 to C6, but never from fractures of L3 to L5. This is because vertebrae C5 to C6
are smaller and more fragile than vertebrae L3 to L5
-
The innermost meninx around the spinal cord is called the___ and extends beyond the medullary cone as the___
pia mater; filum terminale
-
The ventral root carries ____ neurons, while the dorsal root carries ____ neurons.
motor; sensory
-
Anesthetics and anti-inflammitory drugs are introduced into this space in the spinal cord
epidural
-
individuals with parkinsons disease do not produce enough dopamine. Injections of dopamine do not help either. This is because?
it cannot cross the blood-brain barrier
-
Two cranial nerves involved in taste are
facial (VII) and glossopharyngeal (IX)
-
The white matter of the cerebellum constitutes its
arbor vitae
-
Almost all sensory signals pass through the ___ on the way to the cerebrum
thalamus
-
_____ connect one gyrus to another within the same cerebral hemisphere
association tracts
-
The ____ contains nuclei that control coouching, sneezing, swallowing, and vomiting
medulla oblongata
-
The brain center most concerned with emotion is
the limbic system
-
Which of the following nerve endings are not found in the skin?
proprioceptors
-
The loudness of a sound is correlated with the ___ of the sound wave
amplitude
-
Other than the optic disc, the only point where the retina is attached to the rest of the eyeball is an anterior ring called
the ora serrata
-
When the stapes pushes in and creates pressure on the endolymph, the ___ bulges out to relieve the pressure
secondary tymanic membrane in the round window
-
The sensory cells of hearing are stimulated by the ___ resting on their stereocilia
basilar membrane
-
We sense rotary movements of the head when the endolymph pushes on a gelatinous cap called the ___ on a semicircular duct
cupula
-
What is part of the fibrous tunic of the eye?
the sclera
-
The blind spot in each visual field is a region in which
the iris casts a shadow on part of the retina
-
The footplate of the stapes covers an opening called
the oval window
-
Suppose you are sitting in a rotating chair in a hair salon with your eyes closed, and the chair was rotated. you could sense this by means of your
semicircular ducts
-
The function of the suspensory ligaments is to
hold the lense of your eye in place
-
Tate buds are found on all the lingual papillae except for the ___ type.
fungiform
-
The ___ is attached to the medial side of the typanic membrane.
malleus
-
The ____ nervous system carries brain and spinal cord signals to other organs
central
-
The corpus callosum is composed of
commissural fibers
-
cerebrospianl fluid serves what functions
cushion the brain from blows and provide a stable chemical environment for the nervous tissue
-
The primary somesthetic cortex monitors which senses
tickle and touch
-
The cerebrum and cerebellum contains thick folds or ridges called___ whose purpose is to____.
gyri; increase surface area
-
the second largest region of the brain is the___, whose function is to____.
cerebellum; coordinate skeletal muscles
-
The neurons and all glial cells except microglia are derived from embryonic tissue called ___ that thickens to form a structure called the ____ in the third week of embyronic development.
ectoderm; neural plate
-
the lumen of the neural tube develops into the
central canal and ventricles
-
The outer double meningeal layer around the brain is called the _____, and in some places the two layers are seperated by the ___
dura mater; dural sinuses
-
the trigger zone of a neuron indludes
the axon hillock
-
the symptoms of ___ are high fever, stiff neck, drowziness, and intense headache
meningitis
-
a network of capillaries in the brain that produce CSF is called the ___ and is surrounded y glial cells called _____.
choroid plexus; ependymal cells
-
The blood brain barrier is most permeable to which chemicals
glucose, water, oxygen, alcohol, and caffeine
-
Neurons that send impulses to skeletal muscles have a ___ diameter and are ___.
large; myelinated
-
In this disorder, oligodendrocytes and myelin sheaths of the CNS deteriorate and are replaced by hardend scar tissue
multiple sclerosis
-
Damaged neurons in the PNS can regenerate if their ___ is in tact and they can form a ____.
soma; regeneration tube
-
which sensory funciton involves neurons in the dorsal root ganglia?
touch
-
The cerebellum develops from the embryonic
metencephalon
-
What is most concered with motor coordination and equilibrium?
the cerebellum
-
Which lobe of the cerebrum is most concered with vision
the occipital lobe
-
CSF returns to the bloodstream by way of
the arachnoid villi and dural sinuses
-
Damage to the temporal lobe would most likely cause the individual to be unable to
hear
-
What is under dual control of the ANS
iris, heart, salivary glands, digestive system
-
This group of nerves does not come from the brian or spinal cord
enteric
-
Most parasympathetic fibers reach their target organs by way of
the vagus nerve
-
The ___ system is characterized by long preganglionic and short postganglionic fibers
craniosacral
-
What is not controlled by the autonomic nervous system
skeletal muscle
-
in response to high blood pressure, stretch receptors called ___ in the walls of the arteries carrying blood to the heart will cause the heart to ___ its beats per minute.
baroreceptors; decrease
-
The system that stimuates normal conditions in the body such as lowered heart rate, and increased gastrointestional activites such as digestion, secretion, and defecation is the
parasympathetic division
-
The somas of somatic motor neurons are found in the __ of the spinal cord, while the somas of preganglionic neurons of the sympathetic division are found in the ___ of the spinal cord.
ventral horns; lateral horns
-
In the ANS the preganglionic neuron releases ___, while the postganglionic neuron releases ___
ACh; ACh or NE
-
All receptors for ___ are confined to the head and are innervated by cranial nerves
the special senses
-
The receptors for taste are located on
stereocillia on gustatory cells
-
these cells are the only neurons in the body exposed to the external environment, and unlike most neurons, they are replaceable.
olfactory cells
-
the aqueous humor is secreted by the ___ and reabsorbed into the ____.
cilliary body; sclera venous sinus
-
What is most concerned with motor coordination and equilibrium?
the cerebellum
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