Card Set Information
What type of surface coats the superficial surface of the cerebrum?
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?
What connects left and right thalamus together?
What is function of the thalamus?
relay center, primarily for afferent signals en route to the cortex
What makes up the corpus striatum?
What type of matter makes up caudate nucleus?
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?
Glubus palladius (palladium)
What is the lateral part of the lentiform nucleus?
What is the medial part of the lentiform nucleus?
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?
What separates the posterior parts of the caudate nucleus and the putamen?
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?
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?
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?
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?
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?
What do the fornix bodies run directly inferior to?
the corpus callosum
What part of the brain does the fornix belong to?
What are the posterior descending parts of the fornix called?
What kind of matter makes up the body and columns of the fornix?
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?
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
: 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?
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?
From what other cerebral structures does the corpus striatum receive signals?
primary motor cortex (excitatory)
somatosensory cortex (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?
What is the most commonly used excitatory neurotransmitter in the brain?
What type of signal is sent between the putamen and the globus palladius?
Where does the efferent output of the corpus striatum go to?
What type of signal does the substantia nigra receive from the corpus striatum?
connection pathway called "striatonigral" fibers
Where does the globus palladius send inhibtory fibers?
With what kind of fibers does the thalamus connect to the cerebral cortex?
this completes a loop...
What chemical is used for inhibition?
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?
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)
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?
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?
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?
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?
anterior thalamic nuclei
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?
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
autonomic reaction to emotions
What are the functions of the posterior portion of the Cingulate Cortex (gyrus)?
What does the posterior portion of the cingulate cortex (gyrus) merge with?
this then becomes the hippocampus
What is the combined function of the parahippocampal gyrus and the hippocampus?
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?
What other structures are connected to the amygdala?
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?
What is the cause of Alzeimer's disease?
loss of pyramidal neurons
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
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
What is the thickest meningeal layer?
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?
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?
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?
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?
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?
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?
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?
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
What are the horns of the left and right lateral ventricles?
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
What type of process makes CSF?
active, pressure independent
constantly occuring in the choroid plexi of all four ventricles
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?
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
What is the color of CSF?
clear and colorless
What problem causes CSF to not be clear and colorless?
blood-barrier breaks down
proteins and macromolecules enter CSF causing cloudy appearance
What are the functions of the CSF?
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 H
What causes idiopathic intracranial hypertension?
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?
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)?
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)
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
: 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)
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?
medial longitudinal fasciculus (MLF) (CN III, IV, & VI)
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?
Where do somatic efferent axons come from for CN IX?
soma of the
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
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?
What are visceral sensations of the carotid body called?
What type of nerve is CN X (vagus)?
sensory and motor
What cranial openings does CN X (vagus) travel through?
Where do somatic motor axons of CN X (vagus) travel to?
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?
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?
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?
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
What muscles does the spinal root of CN XI (accessory) innervate?
What cranial openings does CN XI (accessory) travel through?
spinal root enters skull via
both spinal and cranial roots exit skull via
What nucleus do cranial root axons of CN XI (accessory) arise from?
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...)
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?
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)
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?
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?
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?
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
Where is the primary motor cortex located?
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?
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
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?
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?
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?
2 occipitotemporal gyri (mostly in temporal lobe)
What are the main gyri of the temporal lobe?
What are the main sulci of the temporal lobe?
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)
What is function of the limbic lobe?
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?
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?
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?
What is the function of cells of Martinotti?
What is the function of chandelier cells?
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
the stria of Gennari (
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?
External granular layer
External pyramidal layer
Internal granular layer
What type of fibers mostly make up the Molecular layer of cortex?
(pyramidal dendrites, stellate and Martinotti axons, horizontal cells)
What layer of cortex is most superficial?
How many sunapses occur in the Molecular layer of cortex?
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
cells of Martinotti
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?
superior temporal gyrus
What type of fibers project to the cells of granular type cortex layers?
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?
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
What percent of people are left hemisphere dominant?
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?
Where do pyramidal cells from dominant hemisphere of brain decussate to innervate the dominant hand?
Where is perception of language and speech located? (dominant or non-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)?
Where is face recognition located (dominant or non-dominant hemisphere)?
Where is music understanding located (dominant or non-dominant hemisphere)?
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?
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?
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?
What is the function of the somatic sensory association area?
integrates all manner of sensory information
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?
What Broadman's area number is the primary visual area?
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?
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,
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?
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
inferior colliculus of midbrain
medial geniculate nucleus (MGN)
primary auditory cortex
What is the connection of ears to brain? (ipsilateral, bilateral, or contralateral)
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
What is function of the secondary auditory area?
associate sounds with other senses
especially correlates sound and eye movement
Where is the primary motor area located?
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?
commissural fibers (from other primary motor cortex)
What muscles get innervated by the primary motor area?
mostly contralateral muscles
some bilateral muscles
What muscles receive bilateral innervation from primary motor area?
Where is the secondary motor area located?
anterior precentral gyrus
posterior portions of:
superior frontal gyrus
The secondary motor area is how many times larger than the primary motor area?
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?
from internal cues and preprogrammed motor movements
"General of motor cortices if primary motor cortex is foot soldier"
What are th association cortical areas?
Anterior temporal cortex
Posterior parietal cortex
What is the function of the prefrontal cortex?
Where is the prefrontal cortex located?
covers most of superior, middle, and inferior frontal gyri
anterior cingulat gyrus
What other parts of the brain does the prefrontal cortex have afferent and efferent connections with?
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?
What are the names of cortical eye fields? (6)
Frontal eye field
Dorsolateral prefrontal cortex (DLPC)
Supplementary eye field
Broadman's area 22
Where are the frontal eye fields located?
middle frontal gyrus
What other eye fields are the frontal eye fields connected to?
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
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?
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?
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?
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?
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?
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?
Which colliculi of the corpora quadragemini deal with hearing?
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?
What is the function of the red nucleus?
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