-
What type of surface coats the superficial surface of the cerebrum?
grey matter
-
What are basal nuclei?
isolated centers of grey matter and neuronal soma within the white matter of the cerebrum
-
What part of the brain does the thatlamus belong to?
diencephalon
-
What connects left and right thalamus together?
interthalamic adhesion
-
What is function of the thalamus?
relay center, primarily for afferent signals en route to the cortex
-
What makes up the corpus striatum?
- cuadate nucleus
- lentiform nucleus
-
What type of matter makes up caudate nucleus?
grey matter
-
Where is the caudate nucleus located?
- it is a C-shaped structure that starts anterior to the lentiform nucleus
- stretches superiorly and posteriorly over the thalamus
- descends and runs anteriorly, inferior to the lentiform nucleus
- tail never touches thalamus
-
What is the shape of the lentiform nucleus?
oval or "lens" shaped...
-
What are the two parts of the lentiform nucleus?
- Putamen
- Glubus palladius (palladium)
-
What is the lateral part of the lentiform nucleus?
putamen
-
What is the medial part of the lentiform nucleus?
globus palladius
-
What is the putamen adjacent to?
inferior portion of the caudate nucleus head
-
What is the putamen made of?
grey neuronal soma and axons
-
What does anterior part of putamen join with?
caudate nucleus
-
What separates the posterior parts of the caudate nucleus and the putamen?
internal capsule
-
Why are the lentiform nuclei and the caudate nuclei known as teh corpus striatum?
strands that connect the two nuclei cause a striped appearance
-
What makes up the globus palladius?
- grey matter, but a lighter grey than putamen
- has some myelinated fibers
-
What divides globus palladius from putamen?
a thin strip of white matter
-
What makes up the claustrum?
grey matter and neuronal cell bodies
-
Where is the claustrum located?
lateral to the lentiform nucleus
-
What is the function of the claustrum?
UNKNOWN
-
What separates the claustrum from the lentiform nucleus?
the external capsule (made of white matter)
-
What lies laterally to the claustrum?
the extreme capsule
-
What is superficial to the extreme capsule?
insular cerebral cortex
-
What travels between the extreme capsule and the insular cortex?
white matter fibers
-
What makes up te amygdala?
- grey matter
- it is a nucleus
-
Where is the amygdala located?
emerges from the anterior end of the tail of the caudate nucleus
-
What is the amygdala related to functionally?
- limbic system
- visceral changes to emotions, pain, and fear respone
-
What is the hippocampus an extension of?
cerebral cortex of the medial temporal lobe
-
What makes up the hippocampus?
- neuronal soma
- grey matter axons
-
where does the hippocampus send its axons?
to the fornix
-
Where is the hippocampus located
- deep temporal lobe
- starts anteriorly and extends posteriorly
-
What is the relation of the hippocampus and the fornix?
the fornix takes information from the hippocampus to other parts of the brain, specifically to the mammillary bodies
-
What is function of hippocampus?
involved in transfroming short-term memories into long-term
-
What system is the hippocampus part of?
limbic system of brain
-
Where do hippocampus axons connect to in the fornix?
the crura (singular is crus)
-
What attaches right and left fornixes?
commissural attachments
-
What do the fornix bodies run directly inferior to?
the corpus callosum
-
What part of the brain does the fornix belong to?
diencephalon
-
What are the posterior descending parts of the fornix called?
columns
-
What kind of matter makes up the body and columns of the fornix?
white matter
-
Where do the anterior tracts of the fornix end?
the septal nuclei of the frontal lobe
-
Where do the posterior tracks of the fornix end?
mammillary bodies of the diencephalon
-
What are mammillary bodies involved in?
processing memories
-
What makes up the internal capsule?
- white matter axons that enter the cerebrum from the thalamus
- white matter axons leaving the cerebrum for the diencephalon, brainstem, and spinal cord
-
Where is the anterior limb of the internal capsule located?
it runs between the superior portions of the putamen and caudate nuclei
-
Where is the posterior limb of the internal capsule located?
runs between the putamen and the thalamus
-
Where do the optic radiations exist?
the most posterior portion of the posterior limb of the internal capsule
-
Where do optic radiations come off?
LGN of the thalamus
-
What is the retrolentiform portion of the internal capsule?
the most posterior portion of the internal capsule, posterior to the lentiform nucleus
-
What must all white matter fibers travel through going to or from the brainstem from the cerebrum?
the two cerebral peduncles of the midbrain
-
What is the corona radiata?
- collection of white matter fibers that project from the internal capsule to the cerebral cortex, or vice versa
- basically an extension of the internal capsule
-
What are association fibers in the cerebrum?
- white matter fibers that connect different parts of the cerebrum within the same himispheres
- two types: long and short
-
What are short association fibers?
white matter fibers that connect areas of cerebral cortex from different gyri within the same cerebral lobe
-
What are long association fibers?
white matter fibers that connect areas of the cerebral cortex from different lobes within the same cerebral hemisphere
-
What are commissural fibers?
- white matter fibers that connect portions of the cerebral cortex in one hemisphere with its partner in the other hemisphere
- there are only four cerebral commissures: corpus callosum, anterior commissure, posterior commissure, and habenular commissure
-
What is the largest cerebral commissure?
corpus callosum
-
What are the parts of the corpus callosum?
- rostrum (most anterior)
- genu (knee or bend)
- trunk or body
- spenium (most posterior)
-
What direction, in relation to the corona radiata, do commissural fibers run?
perpendicular, so they are not the same thing, but they do pass through it.
-
What do the anterior commissural fibers connect?
- olfactory tracts to each other
- limbic system to both halves
-
What do the posterior commissural fibers connect?
decussate axons from the pretectal nuceli travelling ton the Edinger-Westphal nucelus
-
Where is the posterior commissure located?
- between the temporal lobe and the thalamus edges
- superior to the posterior midbrain
-
Where is the anterior commissure located?
the edge between the frontal lobe and the thalamus
-
Where is the Habenular commissure located?
superior to the posterior commissure
-
What does the habenular commissure connect?
axons from the habenular nucleus to go to the contralateral thalamus
-
What do projection fibers travel through?
corona radiata and internal capsule
-
What is the function of the corpus striatum?
- coordination, grading, learning, planning, and regulating of fine motor activity
- maybe some emotional movements
-
What type of input does the corpus striatum receive?
excitatory afferent
-
From what other cerebral structures does the corpus striatum receive signals?
- primary motor cortex (excitatory)
- somatosensory cortex (excitatory)
- thalamus (excitatory)
- nigrosstriatal fibers from the substantia nigra of the brainstem (inhibitory)
- all over the cerebral cortex
-
What is is released into the corpus striatum from fibers?
glutame
-
What is the most commonly used excitatory neurotransmitter in the brain?
glutame
-
What type of signal is sent between the putamen and the globus palladius?
inhibitory
-
Where does the efferent output of the corpus striatum go to?
- substantia nigra
- globus palladius
-
What type of signal does the substantia nigra receive from the corpus striatum?
- inhibitory
- connection pathway called "striatonigral" fibers
-
Where does the globus palladius send inhibtory fibers?
- thalamus
- subthalamus
- midbrain
-
With what kind of fibers does the thalamus connect to the cerebral cortex?
- excitatory
- this completes a loop...
-
What chemical is used for inhibition?
GABA
-
What are nigrostriatal fibers?
- fibers traveling from the substantia nigra to the corpus striatum that release dopamine
- this causes an inhibitory effect on the corpus striatum
-
What are striatonigral fibers?
- fibers that travel from the corpus striatum to the substantia nigra and release GABA
- this causes an inhibitory effect on the substantia nigra
-
What can interruptions of the corpus striatum system cause?
movement problems
-
What is basic function of the corpus striatum?
filters information from the cortex, returns it to the cortex which then sends it to spinal cord or cranial nerves
-
What causes Huntington's chorea?
striatonigral axons degenerate, causing the substantia nigra to be oeveractive and inhibit the corpus striatum too much
-
What type of disease is Huntington's chorea?
hereditary, autosomal dominant
-
What are symptoms of Huntington's chorea?
- involuntary twitching (when staying still)
- immobility
- death
-
How is St. Vitus' dance contracted?
- it is a residual effect from Rheumatic fever that causes an autoimmune disease
- overactive immune system attacks basal nuclei neurons
-
What are symptoms of St. Vitus' Dance?
- twitching
- jerky movements
- usually not too serious and can recover
-
What cause Parkinson's Disease?
- nigrostriatal neurons die
- corpus striatum is no longer inhibted and is overactive
-
What are symptoms of Parkinson's Disease?
- jerky movements
- hunched over due to flexor muscles being activated
- difficulty in stopping or starting movement
- tremors occur when they move
-
How many nigrostriatal fibers must die before Parkinson's Disease symptoms occur?
60%
-
What are treatments for Parkinson's disease?
- L-dopa (dopamine that crosses blood-brain barrier)
- MAOI (monoaminoxidase inhibitors)
- implant neurons that release dopamine
- remove globus palladius (last resort)
-
What are the parts of the Limbic System?
- hippocampus
- fornix
- mammillary bodies
- anterior thalamic nuclei
- amygdalae
- olfaction system
- cingulated gyrus
- parahippocampal gyrus
-
What is function of the Papez circuit?
- transforming short-term memory into long-term memory
- controlls interaction between the autonomic nervous system, endocrine system, and emotions
-
What are the components of the Papez circuit?
- Cingulate cortex
- Parahippocampal gyrus
- Hippocampus
- Mammillary bodies
- Anterior nucleus of the thalamus
-
What are the functions of the anterior portion of the Cingulate Cortex (gyrus)
- motor decision making
- sentence structure in speech
- emotions
- autonomic reaction to emotions
- bladder control
-
What are the functions of the posterior portion of the Cingulate Cortex (gyrus)?
pain perception
-
What does the posterior portion of the cingulate cortex (gyrus) merge with?
- parahippocampal gyrus
- this then becomes the hippocampus
-
What is the combined function of the parahippocampal gyrus and the hippocampus?
- memory transmission
- little computation
-
Where do axons travel to from the mammillary bodies?
anterior nucleu of the thalamus
-
Where does the anterior nucleus of the thalamus send axons?
the anterior cingulate gyrus
-
Where is fear mediated?
amygdala
-
What other structures are connected to the amygdala?
- olfactory tracts
- septal nuclei
- diencephalon
- midbrain
-
What is different about the amygdala than other limbic system structures?
it is not part of the papez circuit
-
What is one theory of phobia creation?
- early, fearful amygdaloid reactions to stimuli before the hippocampus was fully developed
- basically, you feel fear for something but don't remember why you first felt it
-
What causes Post-traumatic stress disorder? (neurologically speaking...)
- strong inputs to te amygdala from cerebral cortex after intense sensation
- can affect hippocampus and long-term memory
- flashbacks are triggered by certain stimuli
-
Can visual stimuli cause flashbacks?
yes, because the visual cortex is connected to the amygdala
-
What is the function of the magnocellular (neuroendocrine) basal nucleus of Meynert
- nucleus of cholinergic fibers that release acetylcholine to all areas of the cerbral cotex when person is awake
- makes brain more sensitive to excitation
- this aids in learning
-
What is the most common cause of dementia?
Alzheimer's disease
-
What is the cause of Alzeimer's disease?
- loss of pyramidal neurons
- Amyloid plaques
- neurofibrillary tangels
- loss of cholinergic neurons from basal nuclei of Meynert
-
What is function of pyramidal neurons?
take motor information from the precentral gyrus to the striated muscles
-
Where are and what are neurofibrillary tangles typically located in Alzheimer's disease?
- located in the hippocampus and amygdala
- they are abnormal clumps of microtubules
-
What is the progression of degeneration of Alzheimer's disease?
- starts in medial temporal lobe and moves superiorly
- then moves occipitotemporally
- finaly, frontal lobe functions dwindle by 3 years of onset
- personality degrades about 5-6 years before death
-
What is the order of function loss in Alzheimer's disease?
- forgetfulness, attention deficit
- inability to read, write, or recognize family
- vacant state
- personality degradation
-
What is interesting in the relationship between cell phones and Alzheimer's disease?
cell phone usage correlates with lower amyloid plaques
-
What are meninges?
- membranes that surroind the CNS, support it, and protect it
- Dura mater
- Arachnoid mater
- Pia mater
-
What is the thickest meningeal layer?
dura mater
-
What are the layers of the dura mater?
- outer endocranial layer
- inner meningeal layer
-
What is the outerendocranial layer of the dura mater attached to?
bone (skull)
-
What artery supplies most of the outer endocranial layer of the dura mater?
middle meningeal branch of the maxillary artery
-
When the inner meningeal layer of the dura mater splits from the outer endocranial layer, what does it form usually?
dural sinuses
-
What meningeal structure divides right and left cerebral hemispheres?
falx cerebri of inner meningeal layer of dura mater
-
Where is the location of the falx cerebri?
- it runs in the midsaggital line of the cranium from frontal bone to occipital bone above the corpus callosum
- ends on the tentorium cerebella
-
What dural structure divides the cerebrum from the cerebellum?
tentorium cerebelli
-
What is the location of the tentorium cerebelli?
- starts on occipital protuberance above the confluence of sinuses
- runs parallel with the transverse sinus along the petreous temporal bone
- ends on the posterior clinoid processes of sella turcica
- pretty much a 300 degree structure with a big whole in the middle
-
Where are the clinoid processes located?
on the lateral sides of the posterior rim (dorsum sellae) of the sella turcica
-
What structure of dura mater does the brain stem exit through?
the tentorial notch of the tentorium cerebelli
-
What makes swelling of the cerebrum or brain stem dangerous in relation to the tentorial notch?
the tentorial notch is sharp and can cause damage to structures when there is extra pressure
-
What is the dura mater structure that covers the sella turcica?
diaphragma sellae
-
What structure passes through the diaphragma turcica?
the infundibulum that connects the pituitary gland to the hypothalamus
-
What forms the diaphragma sellae?
anterior junction of the tentorium cerebelli and the falx cerebri
-
What dura mater layer is continuous with the periosteum (deepest layer) of the scalp?
endosteum
-
What dura mater layer is continous with the epineurium (out covering of nerves)?
inner meningeal layer
-
What is the arachnoid mater attached to?
the inner meningeal layer of the dura
-
Where does blood pool if it comes from injured dural meningeal arteries? What is this called?
- pools between the dura and arachnoid maters
- called a subdural hematoma
-
What is the subdural space?
- a space that only exists if conditions are right, such as a blow to the pterion
- the actual formation of it is usually a bad thing
-
How does CSF get into dural sinuses?
arachnoid villi (also called granulations) penetrate the inner meningeal layer of the dura into the dural sinuses and CSF leeks through this penetration
-
Besides dural sinuses, where is CSF located?
subarachnoid space
-
What is structure of the subarachnoid space?
webby-looking processes that stretch between arachnoid mater and pia mater
-
What is the function of the subarachnoid space?
to act as a shock absorber through the stretchy processes of the arachnoid mater and the CSF contained in it
-
What can be formed between pia mater and arachnoid mater due to the folding of the brain?
cisterna; arachnoid mater does not follow sulci of cerebrum
-
What are the names of large cisterna?
- Cisterna cerebellomedullaris (between the cerebellum and medulla)
- Cisterna interpeduncularis (between the cerebral peduncles)
- Cisterna pontis (between the medulla and the pons)
- Cistern of great cerebral vein
-
What is the thinnest meningeal layer of the brain?
pia mater
-
What is the pia mater connected to?
the CNS; it follows sulci and gyri of the brain and spinal cord intimately
-
What do blood vessels travel through just before supplying the CNS?
invaginations of the pia mater
-
Where is CSF produces?
ventricles of the brain
-
How many cerebral ventricles are there? What are their names?
- Left and right lateral ventricles
- Third ventricle
- Fourth ventricle
-
What are the horns of the left and right lateral ventricles?
- anterior
- occipital
- inferior (temporal)
-
What structure drains lateral ventricles to third ventricle?
interventricular foramena (right and left)
-
Where is the third ventricle located?
- between the right and left diencephalon
- the interthalamic adhesion passes through center of it
-
What drains the third ventricle to the fourth ventricle?
the cerebral aquaduct
-
Where is the fourth ventricle located?
- pons and medulla of brainstem make up anterior border
- cerebellum is posterior border
-
What does CSF pass through to exit subarachnoid space?
- right and left lateral apertures
- median aperture
-
What type of process makes CSF?
- active, pressure independent
- constantly occuring in the choroid plexi of all four ventricles
-
What solely forms the blood brain barrier?
zonula occludens of the endothelial cells of capillaries
-
What type of molecules can diffuse through the blood brain barrier?
-
Where are places in the CNS where the blood-brain barrier does not occur?
- Pineal Gland
- posterior lobe of the pituitary gland
- wall ofthe optic recess
- vascular area postrema
-
What is the function of the pineal gland?
- releases hormones into the bloodstream based upon blood chemistry
- releases hormones into the third ventricle that diffuse to the optic recess area
-
Where is the Vascular area Postrema located? What is its function?
- in the medulla oblongata, on the floor of the fourth ventricle
- vomiting
-
What is the color of CSF?
clear and colorless
-
What problem causes CSF to not be clear and colorless?
- meningitis
- blood-barrier breaks down
- proteins and macromolecules enter CSF causing cloudy appearance
-
What are the functions of the CSF?
- protection
- supportive
- hormone carrying
- remove neuronal biproducts
-
What forms the blood-CSF barrier?
- zonula occludens between the ependymal cells of the choroid plexi capillaries that line the ventricles
- water can be actively transported into CSF using ATP
-
What is normal pressure of the CSF?
60-150 mm H2O
-
What causes idiopathic intracranial hypertension?
UNKNOWN
-
What is pseudotumor cerebri and what are its symptoms?
- increased cranial pressure
- swollen optic disc
- no tumor in imaging
-
Who is at risk for pseudotumor cerebri?
fat, fertile females
-
What is the typical treatment for a pseudotumor cerebri?
heavy duty diuretics
-
What is the circulation (pathway) of the CSF?
- ventricles
- subarachnoid space
- dural venous sinuses
- venous blood supply
-
What type of process is CSF drainage into the venous sinuses?
- passive, pressure dependant
- only happens of CSF pressure is greater than blood pressure
-
Where are most arachnoid villi (granulations) located?
superior sagittal sinus
-
What type of nerve is CN VIII (Vestibulocochlear)?
- purely afferent
- hearing and balance
-
What cranial openings does CN VIII (vestibulocochlear) go through?
internal acoustic meatus
-
What is the pathway of a hearing stimulus? (8 steps)
- spiral organ of Corti
- spiral ganglion (no synapses)
- cochlear nerve
- travels through internal acoustic meatus
- travels in cranial fossa (joins vestibular nerve here)
- enters brain at pontine-medullary junction
- anterior or posterior cochlear nuclei
- end on synapses going to thalamus
-
What is the pathway for cochlear information to the auditory cortex of temporal lobe?
- some go directly to thalamus
- Others: inferior colliculus then thalamus
- from thalamus to auditory cortex of temporal lobe
-
What detects balance?
- ampullae of the semi-circular canals
- maculae of the utricle and saccule by hair cells
-
What is the pathway of the balance stimuli?
- hair cell neurons of the vestibule
- vestibular ganglion (no synapses)
- vestibular nerve
- enters at internal acoustic meatus
- enter brain at pontine-medullary junction
- vestibular nuclei of pons and medulla (lateral, medial, superior, and infereior)
-
Where does balance information travel to after the vestibular nuclei of the pons and medulla?
- the cerebellum
- spinal cord
- medial longitudinal fasciculus (MLF) (CN III, IV, & VI)
- thalamus
- post-central gyrus
-
What type of nerve is CN IX (glossopharyngeal)?
efferent and afferent
-
Where do efferent fibers of CN IX (glossopharyngeal) travel to?
- parasympathetic to parotid gland
- somatic to stylo-pharyngeus
-
Where do afferent fibers of CN IX (glossopharyngeal) travel from?
- somatosensory and taste from posterior 1/3 of tongue
- sensory from middle ear cavity and pharynx
- visceral sensory from carotid body and sinus
-
What cranial openings does CN IX (glossopharyngeal) travel through?
jugular foramen
-
Where do somatic efferent axons come from for CN IX?
soma of the nucleus ambiguous of medulla
-
What innervates the stylopharyngeal muscle? what is its function?
- CN IX (glossopharyngeal)
- active in swallowing
-
What is the pathway of the autonomic afferent axons of CN IX (glossopharyngeal)?
- arise from inferior salivatory nucleus of medulla
- join with glossopharyngeal nerve
- exit jugular formen then branch off
- travel through tympanic nerve to reenter skull
- form lesser petrosal nerve
- otic ganglion (synapses)
- post-otic-ganglions innervate parotid gland
-
After passing through CN IX (glossopharyngeal) and entering the medulla, what nucleus does taste infromation travel to?
solitary tract nucleus
-
After passing through CN IX (glossopharyngeal), where does somatic sensory information travel to?
the three trigeminal nuclei of brainstem
-
what are the three trigeminal nuclei of the brain stem?
- principal sensory nucleus
- mesenchephalic nucleus
- spinal nucleus
-
Where does middle ear cavity sensory info travel to via what cranial nerve?
- to the trigeminal nuclei
- via tympanic plexus, tympanic nerve, then CN IX (glossopharyngeal)
-
Where do visceral sensations of the carotid sinus and carotid body travel to?
- through CN IX (glossopharyngeal) to solitary tract nucleus of medulla
- some continue on to dorsal nucleus of the vagus nerve
-
What are visceral sensations of the carotid sinus called?
baroreceptive
-
What are visceral sensations of the carotid body called?
chemoreceptive
-
What type of nerve is CN X (vagus)?
sensory and motor
-
What cranial openings does CN X (vagus) travel through?
jugular foramen
-
Where do somatic motor axons of CN X (vagus) travel to?
- pharynx
- palate
- larynx
- upper esophagus
-
Where do somatic motor axons of CN X (vagus) arise from?
nucleus ambiguus of hte medulla
-
Where do parasympathetic motor axons of CN X (vagus) arise from ?
dorsal nucleus of the vagus nerve in the infero-posterior medulla
-
What do parasympathetic motor axons of CN X (vagus) innervate?
- heart
- bronchi
- esophagus
- liver
- kidneys
- pancreas
- digestive tract
-
Where do most organs of the digestive tract have their parasympathetic ganglia?
the organ walls
-
What opening does CN X (vagus) pass through to enter abdomen?
esophageal opening
-
What afferent sensory information does CN X (vagus) carry?
- general and visceral sensation from all innervated structures
- external ear (via auricular branch)
-
What two ganglia of the vagus nerve occur just before the jugular foramen?
- superior sensory ganglia
- inferior sensory (nodose) ganglia
- sensory neuronal somae are found here
-
What nucleus do sensory axons traveling through CN X(vagus) project to?
trigeminal nuclei
-
Is there any taste sensory info that travels through CN X (vagus)?
- very little from epiglottis taste buds
- these project to the solitary tract nucleus
-
What type of nerve is CN XI (accessory)?
purely somatic efferent!
-
What two divisions of CN XI (accessory) are there?
-
What muscles does the cranial root of CN XI (accessory) innervate
- muscles of pharynx
- larynx
- palate
-
What muscles does the spinal root of CN XI (accessory) innervate?
- sternocleidomastoid
- trapezius
-
What cranial openings does CN XI (accessory) travel through?
- spinal root enters skull via foramen magnum
- both spinal and cranial roots exit skull via jugular foramen
-
What nucleus do cranial root axons of CN XI (accessory) arise from?
nucleus ambiguus
-
What do spinal root axons of CN XI (accessory) arise from?
cervical spinal cord in form of rootlets
-
What type of nerve is CN XII (hypoglossal)?
purely motor (somatic) efferent
-
What does CN XII (hypoglossal) innervate?
- intrinsic muscles of the tongue
- extrinsic musles of the tongue
-
What cranial opening does CN XII (hypoglossal) pass through? (it's easy...)
hypoglossal foramen
-
Where do motor axons of CN XII (hypoglossal) arise from?
- somae of hypoglossal nucleus of the medulla
- exit from anterior medulla
-
What additional nerve fibers pass through CN XII (hypoglossal) as it passes through neck?
fibers from cervical plexus
-
What are the grooves, or valleys, of the cerebral cortex?
sulcus
-
What are the peaks between sulci in cerebral cortex?
gyrus (plural gyri)
-
What divides the two hemispheres of the cerbral cortex?
longitudinal cerebral fissure
-
why is vision not affected if corpus callosum is cut?
vision decussates in optic chiasm and never travels in the corpus callosum
-
What divides the brain into its different lobes? (2 main sulci and 2 imaginary lines)
- Central sulcus
- Lateral sulcus/ Sylvian Fissure
- temporal/ parietal division
- temporal/ parietal/ occipital division
-
What does the Central Sulcus divide?
- frontal from parietal lobe
- sits between precentral and postcentral gyri
-
What does the Lateral Sulcus/ Sylvian Fissure divide?
frontal lobe from temporal lobe
-
What lobe lies medial to the temporal lobe and is hidden?
insula lobe
-
What is the landmark for the temporal/ parietal division?
- the lateral sulcus/ Sylvian Fissure
- draw a line from where this ends till the occipital lobe
- everything beneath is temporal lobe
- everything above it and behind central sulcus is parietal lobe
-
What are landmarks for temporal/ parietal/ occipital division?
vertical line going from pareitaloccipital sulcus (on superior posterior part of cerebrum) to preoccipital notch (located on inferior border of cerebrum)
-
What is the cingulate sulcus?
- it is a medial sulcus of the cerebrum only visible from a midsaggital view
- it divides the frontal and parietal lobes from the Limbic lobe
-
What is boundary of frontal lobe from the medial view?
- an imaginary line from the edge of the central sulcus to the cingulated sulcus
- everything behind line is parietal lobe
- everything anterior is frontal lobe
-
What dividing sulcus was relatively small on lateral view, but is large on medial view?
parietaloccipital sulcus
-
What sense is supposedly considered to be the most evocative?
smell, because it feeds directly into limbic area
-
What are the major gyri of the frontal lobe?
- precentral gyrus
- superior gyrus
- middle gyrus
- inferior gyrus
- orbital gyri
- cranial nerve 1/ olfactory bulb
-
What are the major sulci of the frontal lobe?
- superior frontal sulcus (divides superior and middle gyri)
- inferior frontal sulcus (divides middle and inferior gyri)
-
What are the four areas of the frontal lobe?
- primary motor cortex
- secondary motor cortex
- premotor cortex
- prefrontal cortex
-
Where is the primary motor cortex located?
precentral gyrus
-
Where is the secondary motor cortex located?
anterior to the precentral gyrus
-
Where is the premotor cortex located?
- anterior to secondary motor cortex
- parts in the superior, middle, and inferior gyri
-
Where are the frontal eye fields located?
premotor cortex
-
Where is the prefrontal cortex located?
most anterior part of frontal lobe
-
What is the function of the prefrontal cortex?
inhibitory control of behavior
-
What changes in the cerebrum can cause more aggressive behavior?
- removal of prefrontal cortex
- pituitary adenoma
-
What are the functions of the parietal lobe?
- detecting sensory information
- integration of information through association areas
-
What are the main areas of the parietal lobe?
- postcentral gyrus
- inferior parietal lobule
- superior parietal lobule
-
What are the divisions of the inferior parietal lobule?
- supramarginal gyrus (lies on margin of lateral fissure)
- angular gyrus (most posterior area)
-
What additional subdivision does the superior parietal lobule have?
- precuneus
- located directly anterior to cuneus
- separated by parietaloccipital sulcus
-
What houses the primary visual cortex?
calcarine sulcus of the occipital lobe
-
What are the main areas of the occipital sulcus?
- cuneus
- calcarine sulcus
- lingual gyrus
- 2 occipitotemporal gyri (mostly in temporal lobe)
-
What are the main gyri of the temporal lobe?
- superior temporal
- middle temporal
- inferior temporal
- lateral occipitotemporal
- medial occipitotemporal
- lingual
- uncas
-
What are the main sulci of the temporal lobe?
- superior temporal
- inferior temporal
- occipitotemporal
-
What causes death in an uncal herniation?
uncus drops down into tentorial notch from a spinal tap
-
What are the functions of the temporal lobe?
- higher order visual processes
- auditory and olfactory cortices located here
- anterior tip has part of prefrontal cortex (behavior control)
-
What gyrus makes up the limbic lobe? (only one)
cingulate gyrus
-
What is function of the limbic lobe?
- emotions
- memory function
- autonomic nervous system
-
What is the cerebral cortex?
surface of grey matter of the brain
-
Where is the cerebral cortex grey matter thinnest? thickest?
- bottom of sulcus
- top of gyrus
-
What type of neurons do functional units of the cerebral cortex have?
- afferent neurons
- efferent neurons
- interneuron neurons
-
Are functional units of cerebral cortex isolated or linked to others?
- they can exist both ways
- linked by horizontal granular cells
-
What type of Golgi cell are pyramidal cells?
Golgi type I
-
What cells form the main efferent output of the cerebral cortex?
pyramidal cells
-
What are Betz cells?
- the largest of any type of pyramidal cell
- found in the motor cortex
-
What are some attributes of the pyramidal cells?
- receive a single dendrite from superficial molecular layer of cortex
- receive many dendrites from neighboring neurons
- dendrites are highly spined
-
Where can axons of pyramidal cells travel to?
- terminate deep in cortex
- leave cortex in white matter of cerebrum
-
Which general direction in cortex has larger pyramidal cells
deeper in the cortex
-
What type of Golgi neuron are stellate (granule) cells?
Golgi type II
-
What do stellate (granule) cells look like?
short axons and many dendrites
-
What is the function of stellate (granule) cells?
- act as interneurons
- excitatory or inhibitory
-
What is the inhibitory function of stellate (granule) cells?
they refine or focus actions
-
Where are horizontal cells (of Cajal) located?
in superficial cortex
-
What is the function of horizontal cells (of Cajal)?
interneurons running parallel to cortex surface
-
What do cells of Martinotti travel toward?
superficial cortex
-
What is the function of cells of Martinotti?
interneurons
-
What is the function of chandelier cells?
inhibitory
-
Where are cell bodies of afferent neurons in the cortex located?
- not in the cortex unless coming from association axon of pyramidal cell
- come from cell bodies located elsewhere
-
How are radial fibers oriented in the cortex?
- perpendicular to cortex
- they enter and exit cortex
- they are from pyramidal cell axons
-
How are tangential fibers oriented in the cortex?
- parallel to the cerebral cortex
- examples are bands of Baillarger in IV and V
-
What are bands of Baillarger?
- very thick centers of striated cortex fibers in the visual cortex
- they form the stria of Gennari (striate cortex)
-
What band of cortex are thicker in sensory cortex areas?
bands IV and V because of larger amount of sensory fibers
-
What does homotypical cortex mean?
area of cortex with six distinct layers
-
What are the six homotypical layers of cortex?
- Molecular layer
- External granular layer
- External pyramidal layer
- Internal granular layer
- Ganglionic layer
- Multiform layer
-
What type of fibers mostly make up the Molecular layer of cortex?
- tangential fibers
- (pyramidal dendrites, stellate and Martinotti axons, horizontal cells)
-
What layer of cortex is most superficial?
Molecular layer
-
How many sunapses occur in the Molecular layer of cortex?
- many
- a lot
- don't bother counting...
-
What makes up the External granular layer of cortex?
- stellate cell bodies
- pyramidal cell bodies
-
What makes stellate cells so special?
they are the primary interneurons of the cerebral cortex
-
What makes up the External pyramidal layer of cortex?
pyramidal cell bodies
-
What makes up the Internal granular layer of cortex?
- more stellate cell bodies
- band of Baillarger
-
What is the orientation of outer band of Baillarger fibers?
tangentially oriented (mainly efferent)
-
What makes up the Ganglionic layer of cortex?
- larger pyramidal cell bodies
- stellate cells
- cells of Martinotti
- Betz cells
- inner band of Baillarger
-
What makes up the Multiform layer of cortex?
- pyramid cells projecting downward
- cells of MArtinotti
- many axons leaving and entering the cortex
-
What does Heterotypical cortex mean?
- parts of cortex without obvious 6 layers of organization
- makes up 10% of cortex
-
What two types of heterotypical cortex are there?
-
What is distinct about the granular type of heterotypical cortex?
- layers II (external granular) and IV (internal granular) are well developed
- pyramidal layers are not well developed
-
What type of function do granular type cortex areas perform?
receiving information (i.e. vision, hearing, taste, etc.)
-
Where are granular type cortex areas found?
- postcentral gyrus
- superior temporal gyrus
- parahippocampal gyrus
-
What type of fibers project to the cells of granular type cortex layers?
Thalamocortical fibers
-
What makes up agranular type of heterotypical cortex?
- well developed pyramidal layers (Ganglionic layer and external pyramidal layer)
- poor developed granular layers
-
Where is agranular type cortex found?
- precentral gyrus
- all other motor function areas of frontal lobe
-
Are cerebellar cortex layers the same as cerebral cortex?
- no, there are only three layers in typical cerebellar cortex, and they are different from the heterotypical layers of cerebral cortex
- they are likely heterotypical
- they are likely motor
-
What hemisphere of the brain is dominant at birth?
neither, they are identical at birth
-
By what age does one hemisphere fully develop to being dominant
age 5-7
-
What percent of people are left hemisphere dominant?
90%
-
What is the relationship between handedness and brain dominance?
they are contralateral (right handed = left brain dominant)
-
What cells does the dominant part of the brain have more of?
pyramidal neurons
-
Where do pyramidal cells from dominant hemisphere of brain decussate to innervate the dominant hand?
medulla oblongata
-
Where is perception of language and speech located? (dominant or non-dominant hemisphere)
- dominant hemisphere
- damage to same parts of non-dominant side would not cause speech problems
-
Where is spatial perception located ( dominant or non-dominant hemisphere)?
non-dominant
-
Where is face recognition located (dominant or non-dominant hemisphere)?
non-dominant
-
Where is music understanding located (dominant or non-dominant hemisphere)?
non-dominant
-
What type of cortex makes up the primary somatic sensory area?
granular heterotypical cortex
-
What is the orientation of the homunculus on the primary somatic sensory area?
inverted except for the face (i.e. feet are superior to hands, but eyes are superior to mouth
-
What region of body has ipsilateral connections to the homunculus?
oral region
-
What parts of the body have contralateral connections to the homunculus?
most parts with a few exceptions (know the exceptions)
-
What parts of the body have bilateral connections with the homunculus?
- pharynx
- larynx
- perineum (chode, taint, or whatever)
-
Where does main afferent input to the primary somatic sensory area come from?
thalamus, specifically from posterior area
-
What other parts of the cerebrum does the primary somatic sensory area connect with?
- primary motor cortex
- commissural inputs for cross-talk between hemispheres
-
Where do the main efferent axons from the primary somatic sensory area travel?
higher order sensory cortices (i.e. spinal cord)
-
Where is the secondary somatosensory area located?
on the medial surface of the insula lobe
-
What does the secondary somatosensory area mostly deal with?
- pain
- tactile discrimination
-
What is the function of the somatic sensory association area?
- integrates all manner of sensory information
- stereognosis
- reaching of contralateral arm under visual guidance
-
What is stereognosis?
- discrimination without vision
- recognition of something without seeing it by its shape, texture, touch, etc.
-
Where is the Primary Visual area located?
along the walls of the calcarine sulcus of the occipital lobe
-
What kind of cortex is the primary visual area made of?
granular heterotypical
-
What Broadman's area number is the primary visual area?
17!!
-
Where does afferent input to the primary visual area come from?
Lateral geniculate nucleus (LGN) of the Thalamus via optic radiations
-
What do the optic radiations pass through to get to the primary visual area?
parietal lobe and temporal lobe
-
Explain ipsilateral and contralateral input to the primary visual area.
- temporal visual field is ipsilateral
- nasal visual field is contralateral
-
Where does the inferior visual field go to in the primary visual area? superior visual field?
- superior calcarine sulcus wall
- inferior calcarine sulcus wall
-
How much of the primary visual cortex is taken up by the Macula lutea?
- 1/3
- we see very little, but we need more detail
-
What are the Broadman's area numbers for the secondary visual area?
18 and 19
-
What does the secondary visual area receive afferent fibers from?
- primary visual area
- pulvinar of the thalamus
-
What is the function of the pulvinar?
discerning what is visually important through movement or object recognition
-
What is the function of the secondary visual area?
relating visual information to visual memory, in other words, recognition
-
How does the MT region relate to vision?
- it is a higher level cortical area
- involved with spatial/ visual areas
- helps with overall visual experience
-
How is V4 area of temporal lobe related to vision?
- involved with shape/ color perception
- object recognition (especially face recognition)
-
Where is the primary auditory area located?
superior temporal gyrus
-
What type of cortex makes up the primary auditory area?
granular heterotypical cortex
-
How is the primary auditory area organized?
- isofrequency stripes
- posterior stripes are for higher frequencies
-
Where do afferent fibers to the primary auditory area come from?
medial geniculate nucleus of the thalamus
-
What is the pathway of auditory sensation?
- organ of Corti
- cochlear nucleus
- brainstem
- inferior colliculus of midbrain
- medial geniculate nucleus (MGN)
- primary auditory cortex
-
What is the connection of ears to brain? (ipsilateral, bilateral, or contralateral)
bilateral
-
Where is the secondary auditory area located?
superior temporal gyrus and lateral sulcus
-
Where does the secondary auditory area receive fibers from?
- afferent fibers from primary auditory area
- thalamus
-
What is function of the secondary auditory area?
- interpret sounds
- associate sounds with other senses
- especially correlates sound and eye movement
-
Where is the primary motor area located?
- precentral gyrus
- paracentral lobule (on medial side of cerebrum)
-
What type of cortex makes up the primary motor area?
agranular heterotypical cortex
-
What does cortiospinal mean?
neural fibers that travel from cortex to the spine
-
What does corticobulbar mean?
neural fibers that travel from cortex to nuclei of brainstem
-
Where do fibers travel to from the primary motor area?
- corticospinal (to spine)
- corticobulbar (to nuclei of midbrain)
-
Where does afferent information of the primary motor area come from?
- sensory cortex
- commissural fibers (from other primary motor cortex)
- cerebellum
- premotor cortex
- thalamus
- basal nuclei
-
What muscles get innervated by the primary motor area?
- mostly contralateral muscles
- some bilateral muscles
-
What muscles receive bilateral innervation from primary motor area?
- extraocular
- tongue
- mandible
- upper face
- larynx
- pharynx
-
Where is the secondary motor area located?
- anterior precentral gyrus
- posterior portions of:
- superior frontal gyrus
- middle ""
- inferior ""
-
The secondary motor area is how many times larger than the primary motor area?
six times
-
What is the function of the secondary motor area?
controls motor activity patterns
-
Where is the supplementary motor area located?
medial surface of the middle frontal gyrus
-
What is the function of the supplementary motor area?
- motor planning from internal cues and preprogrammed motor movements
- "General of motor cortices if primary motor cortex is foot soldier"
-
What are th association cortical areas?
- Prefrontal cortex
- Anterior temporal cortex
- Posterior parietal cortex
-
What is the function of the prefrontal cortex?
- determines personality
- feelings
- initiative
- judgement
-
Where is the prefrontal cortex located?
- covers most of superior, middle, and inferior frontal gyri
- orbital gyri
- anterior cingulat gyrus
-
What other parts of the brain does the prefrontal cortex have afferent and efferent connections with?
- cerebral cortex
- thalamus
- hypothalamus
- corpus striatum
-
What is the function of the anterior temporal cortex?
- stores sensory experiences
- recall of objects seen and music heard
-
What is the function of the posterior parietal cortex?
- proprioception
- stereognosis
-
What are the names of cortical eye fields? (6)
- Frontal eye field
- Occipital ""
- Dorsolateral prefrontal cortex (DLPC)
- Cingulate cortex
- Supplementary eye field
- Broadman's area 22
-
Where are the frontal eye fields located?
- precentral gyrus
- middle frontal gyrus
-
What other eye fields are the frontal eye fields connected to?
- occipital
- superior colliculus
-
What is the function of the frontal eye fields?
voluntary scanning eye movements
-
What is the function of the occipital eye fields?
relexative eye movements when following a moving stimulus
-
What are the occipital eye fields connected to?
- contralateral occiptal eye field
- superior colliculus
- frontal eye fields
-
What is the function of the dorsolateral prefrontal cortex (DLPC)?
- voluntary suppression of reflex eye movements
- planning voluntary eye movements
-
What is the function of the cingulate cortex in eye fields?
- assess valence of visual targets
- decision making of what is important or noticeable
-
What is the function of the supplementary eye field?
planning of saccades, especially multiple ones
-
What is the function of Broadman's area 22?
reflex saccades in response to sounds
-
Where is Broadman's area 22 located?
superior temporal gyrus
-
What is the function of the Wernicke-Broca locus?
understanding of language and ability to express language
-
Where is sensory speech area of Wernicke located?
superior temporal gyrus of dominant hemisphere
-
What is the function of the sensory speech area of Wernicke?
understanding of written and spoken language
-
What brain structures does Wernicke's area receive afferent fibers from?
- primary visual cortex
- primary auditory cortex
-
Where does Wernicke's area send efferent fibers?
Broca's area
-
What does a complete injury to Wernicke's area cause?
receptive aphasia (inability to understand spoken word)
-
What does injury to the angular gyrus cause? (next to Wernicke's area)
- alexia (inability to read)
- agraphia (inability to write)
-
Where is the motor speech area of Broca located?
inferior frontal gyrus of dominant hemisphere
-
What is the function of motor speech area of Broca?
control of muscular movements involved in speech
-
What does an injury to Broca's area cause?
expressive aphasia (inability to produce speech)
-
What does an injury to the entire Wernicke-Broca locus cause?
global aphasia (inability to do anything with language)
-
Where is the taste cortical area located?
inferior portion of the postcentral gyrus, along wall of lateral sulcus, and adjoining the insula
-
Where is the vestibular cortical area located?
facial area of postcentral gyrus
-
What is the tuber cinereuma?
a gray-matter protuberance on the inferior diencephalon that becomes the infundibulum
-
What defines the lateral surface of the diencephalon?
internal capsule
-
What is the function of the thalamus?
relay for all sensory systems except olfaction
-
What divides the thalamus' internal structures?
- internal medullary lamina
- it also carries white matter fibers that connect the different thalamic nuclei
-
What is the function of the anterior-superior division of the thalamus?
- contains thalamic nuclei
- receive mammilothalamic tract
- project to the cingulate gyrus
- this is the Papez circuit part
-
What is the function of hte medial-posterior division of the thalamus?
- integration of somatic, olfactory, and visceral information
- relates emotions of these senses
-
What is the function of the lateral-posterior division of the thalamus?
houses a number of nuclei (ventral and dorsal)
-
What are the functions of the ventral anterior and ventral lateral nuclei of the thalamus?
receive information dealing with motor activity
-
What is the function of the ventral posterior nucleus of the thalamus?
- the ventral posterior lateral nucleus receives information from the spinal cord, and projects info to the superior part of primary somatosensory cortex
- the ventral posterior medial nucleus receives sensory info from head, and projects info to inferior part of primary somatosensory cortex
-
What is the pulvinar a piece of and what is its function?
- part of the posterior dorsal thalamus
- involved in visual attention (because it is so close to the LGN...)
-
What is the function of the lateral geniculate nucleus (LGN)?
- optic trac fibers enter here to synapse
- optic radiations leave here to travel to occipital lobe
- it is made up of 6 concentrically arranged layers of cortex
-
What is the function of the medial geniculate nucleus (MGN)?
- receives auditory information from both ears (mainly contralateral)
- projects to auditory cortex via auditory radiations
-
What does subthalamus do?
- it is very complicated
- connected to red nucleus, substantia nigra, and corpus striatum
-
What structures are located in the epithalamus?
- habenular nucleus
- hagenular commissure
- pineal gland
-
What is the function of the habenular nucleus?
center for olfactory, visceral, and somatic afferent integration
-
What is the function of the habenular commissure?
decussate fibers from thalamus to go to contralateral habenular nucleus
-
What is the function of the pineal gland?
endocrine gland that influences the entire endocrine system
-
What structure connects the pineal gland to the rest of the diencephalon?
- pineal stalk
- this contains habenular and posterior commissures
-
What are pinealocytes?
- endocrine cells of the pineal gland that secrete inhibitory substances
- melatonin is good example hormone
-
How does the pineal gland affect the retina?
- they are connected through the LGN of the thalamus
- dark and light cycles affect amount of substances secreted
-
What type of matter makes up the hypothalamus' nuclei?
gray matter
-
How does the hypothalamus communicate with other parts of body?
-
Where does the hypothalamus receive information from?
pretty much everywhere in order to maintain homeostasis
-
What type of nerve output does the hypthalamus have?
efferent, but not classified as pre- or postganglionic because they stay within the CNS
-
How is the hypothalamus connected to the pituitary gland?
- nervous connections (infundibulum)
- blood connections (hypothalamic-hypophyseal portal system)
-
What is Diabetes Insipidus?
- caused by a lesion in the hypothalamus
- causes a hormonal imbalance which leads to increased urniation = increased water intake
- has NOTHING to do with blood sugar!
-
Which colliculi of the corpora quadragemini deal with visual reflexes?
superior colliculi
-
Which colliculi of the corpora quadragemini deal with hearing?
inferior colliculi
-
What is the function of the superior brachium of the midbrain?
- part of the lateral surface of the midbrain
- connects superior colliculi with lateral geniculate nucleus (LGN) and optic tract
-
What is the function of the inferior brachium of the midbrain?
connects inferior colliculi with medial geniculate nucleus (MGN)
-
The posterior perforated substance is located where?
anterior portion of midbrain
-
What is the tectum of the midbrain?
- internal, most posterior portion of midbrain
- contains corpora quadrigemina and pretectal nuclei
- located poserior to cerebral aquaduct
-
What surrounds the cerebral aqueduct?
periaqueductal gray matter of the midbrain
-
What divides the tegmentum from the crus cerebri?
substantia nigra
-
What is the function of the red nucleus?
- controlling movement
- receives afferents from cerebral cortex, cerebellum, lentiform nucleus, substantia nigra, and spinal cord
- rubrospinal tract connects red nucleus to the spinal cord
-
What is the function of the crus cerebri?
connects cerebral cortex with the spinal cord, pons, cerebellum, and cranial nerve nuclei
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