CSF, Vessels, and Higher Cortical Structure Flashcards
what are the four regions of the lateral ventricles?
inferior, posterior, anterior horn, and body
how is the lateral ventricle connected to the third ventricle?
interventricular foramen
what is the third ventricle superior to?
the optic chiasm and midbrain
what are the boundaries of the fourth ventricle?
anterior: pons and medulla
posterior: cerebellum
what are the apertures of the fourth ventricle?
paired lateral, single median
what does the fourth ventricle open to inferiorly?
the central canal
what are the cisterns of the ventricular system?
lumbar, cisterna magna, prepontine, interpeduncular, quadrigeminal
what does the choroid plexus do?
filters the plasma from the blood to create CSF
what is the nutrient more concentrated in CSF compared to other bodily fluids?
calcium
what are functions of the CSF?
physical support for the brain, excretory functions allow for the removal of water-soluble metabolites, channel for chemical communication
are choroid capillaries permeable? are choroid epithelial cells permeable?
yes
limited permeability
what do choroid epithelial cells allow through?
lipid soluble substances (O2, CO2)
how is CSF reabsorbed?
absorbed out of the subarachnoid space through arachnoid granulations?
what is another way CSF can be absorbed?
through cervical lymphatics by way of arachnoid surrounding CNs
what is hydrocephalus?
when there is more production of CSF than absorption
what are symptoms of hydrocephalus?
headaches, nausea, motor and sensory disturbances
how is hydrocephalus traditionally treated?
with a ventroperitoneal shunt
what does non-communicating hydrocephalus indicate?
a blockage within the ventricular pathway
what does the anterior cerebral artery perfuse?
medial frontal and parietal lobes
what does the posterior cerebral artery perfuse?
inferior and medial temporal and occipital lobes, posterior thalamus, cerebral peduncles
what does the middle cerebral artery perfuse?
lateral frontal, parietal, occipital, and temporal lobes, insula
what do lenticulostriate arteries perfuse?
basal ganglia, internal capsule, amygdala, anterior thalamus
what are the branches of the basilar artery?
short and paramedian pontine, long circumferential
what do short and paramedian pontine arteries perfuse?
crus cerebri and central pons
what do long circumferential branches perfuse?
dorsolateral pons, superior cerebellar peduncle
what does the superior cerebellar artery perfuse?
superior dorsolateral pons, dorsal midbrain, cerebellum
what does the anterior inferior cerebellar artery perfuse?
inferior dorsolateral pons and cerebellum
what does the posterior inferior cerebellar artery perfuse?
superior dorsolateral medulla and cerebellum
what does the quadrigeminal artery perfuse?
arises from PCA, supplies sup and inf colliculi, and tectum
what do the posterior choroidal arteries perfuse?
posterior thalamus and choroid plexus
there are medial and lateral branches
where does the anterior spinal artery come from? what does is perfuse?
from vertebral arteries
supplies anterior 2/3 of sc
where do the posterior spinal arteries come from? what do they perfuse?
from posterior inferior cerebellar arteries
supplies posterior 1/3 of sc
what are pyramidal cells?
multipolar neurons
main output neurons of the cerebral cortex
what is the size of pyramidal cells related to?
the distance to its target
where are pyramidal cells found?
in cortical layers 2, 3, 5, & 6
what are the classifications of pyramidal cells?
commissural, association, projection
commisural pyramidal cells
form the corpus callosum
association pyramidal cells
go to the ipsilateral cortex
what do projection pyramidal cells do
go to other parts of the CNS (like the sc)
what do stellate cells do?
project to local targets in the cerebral cortex
modulate cortical activity
where are stellate cells found?
in layers 2-6
spiny stellate cells
release glutamate which is excitatory
aspiny stellate cells
release GABA which is inhibitory
what is neocortex?
95% of the cortex with six distinct layers
what is allocortex?
less developed with only 3-4 layers
archicortex
hippocampus/dentate gyrus
paleocortex
olfactory bulb/piriform cortex
what is cortical layer 1 named? what does it contain?
molecular
cell processes
what is cortical layer 2 named? what does it contain?
external granular
dense stellate cells and small pyramidal cells
what is cortical layer 3 named? what does it contain?
external pyramidal
loose stellate cells and medium pyramidal cells
what is cortical layer 4 named? what does it contain?
internal granular
dense stellate cells
what is cortical layer 5 named? what does it contain?
internal pyramidal
large pyramidal cells
what is cortical layer 6 named? what does it contain?
multiform
various sized pyramidal cells and loose stellate cells
what is the function of cortical layer 2?
to ipsilateral cortical areas
what is the function of cortical layer 3?
to contralateral cortical areas
what is the function of cortical layer 4?
input
what is the function of cortical layer 5?
to the striatum, brain stem, and spinal cord
what is the function of cortical layer 6?
to the thalamus
what do projection bundles do?
connect cortex and subcortical structures
what do commissural bundles do?
connect contralateral cortical areas (layer 3)
what do association bundles do?
connect ipsilateral cortical areas (layer 2)
what are examples of association fibers?
superior and inferior longitudinal fasciculus, frontooccipital fasciculus, cingulum, uncinate fasciculus, short fibers
what are Brodmann’s Areas
52 distinct areas based on histological differences in the cortex, don’t respect sulci or gyri boundaries
Brodmann’s areas 1,2,3
primary somatosensory cortex
Brodmann’s area 5
somatosensory association area
Brodmann’s area 4
primary motor cortex
Brodmann’s area 6
premotor cortex
Brodmann’s area 17
primary visual cortex
Brodmann’s area 18, 19
visual association cortex
Broddmann’s area 41
primary auditory cortex (extends across transverse temporal gyrus)
Broca’s area
Brodmann’s area 44,45
inferior frontal gyrus
Wernicke’s area
Brodmann’s area 22,40
superior temporal gyrus and supra marginal gyrus
arcuate fasciculus
connects Broca’s and Wernicke’s
association bundle
what is prosody?
the ability to translate/produce pitch, volume, tempo, and rhythm
(Broca and Wernicke’s areas on right)
what are the reading centers
supra marginal gyrus (40)
angular gyrus (39)
word recognition in occipitotemporal gyrus (37)
word vocalization in Broca’s area (44)
writing in premotor cortex (6)
what happens in dyslexia?
different regions of the brain are activated when trying to read
what does reading center 40 do?
supramarginal gyrus
auditory perceptions, how does the word sound
what does reading center 39 do?
angular gyrus
this is what that word is, auditory representation
what does reading center 37 do?
visual word form area (word recognition) in occipitotemporal gyrus
what does reading center 44 do?
word vocalization in broca’s area, motor planning for vocalization
what does reading center 6 do?
motor plans for handwriting in premotor cortex
