Cerebral Cortex Flashcards
2 purposes of gyri and sulci?
anatomical division and increase surface area
white or gray matter in core and surrounding?
white core, gray surrounding
how is the cortex organized horizontally?
histologically - predominating cell type
how is the cortex organized vertically?
by function
neocortex composed of _ and # layers?
majority of human cortex, 6 layers
paleocortex and archicortex composed of # layers and what two other structures?
3 layers, olfactory bulbs, hippocampus
6 layers of cortex? (1-6 is outer to inner)
molecular, external granular, external pyramidal, internal granular, internal pyramidal, multiform
pyramidal neurons found in which 2 layers?
they provide main _ of the cortex?
3, 5
output (efferent)
granular cells are found in which 2 layers?
main _ cells of cortex?
involved in _ functions?
2, 4
interneurons
afferent/sensory
homotypical vs heterotypical cortex?
homo - can see 6 regular layers
hetero - 6 layers are not recognizable
in heterotypical, what is granular vs agranular?
how well developed the cells are
granular cells are mainly _ integration and found in what 2 layers?
sensory
2, 4
thalamocortical fibers are made of what cell type?
granular (hetero)
agranular type are found mostly in _
they are densely packed with _
primary motor cortex (frontal lobe)
pyramidal cells
subcortical fiber bundles are made of what cell type?
agranular type (hetero)
association fibers connect _
areas of cortex within the same hemisphere
short association connect _
long association connect _
areas in adjacent sulci/gyri
more distant areas of cortex
superior longitudinal fasciculus spreads anterior to _ lobe, and posterior to _ lobes
frontal lobes
parietal occipital
posterior portion of superior longitudinal fasciculus extends into the temporal lobes and is called the _
arcuate fasciculus
arcuate fasciculus connects 2 areas in the left hemisphere?
broca’s area and wenicke’s area
inferior occipitofrontal fasciculus goes through which 3 lobes?
frontal - temporal - occipital
inferior occipitofrontal fasciculus, AKA _
uncinate fasciculus
superior occipitofrontal fasciculus connects which 3 lobes?
frontal, parietal, occipital
superior occipitofrontal fasciculus is close to _
corpus callosum
cingulum connects areas of _
limbic cortex
_ interconnect areas of similar functional activity across 2 hemispheres
commissural fibers
majority of commissural fibers cross at _
corpus callosum
what is the largest cortical commissure
corpus callosum
3 parts of the corpus callosum:
body, splenium (posterior), genu (knee)
anterior commissure connects _ and _
anterior temporal lobes and olfactory bulbs
posterior commissure is located where? and connects what?
midbrain
pretectal nuclei
projection fibers travel to and from which 2 structures?
cortex and thalamus
projection fibers come from all parts of cortex into _
corona radiata
corona radiata converge into compact bundles called _ (V-shaped with bend @ genu)
internal capsule
primary motor cortex is located in _ lobe on _ gyrus
frontal, precentral gyrus
primary motor cortex of left hemisphere sends motor output to _ side of body
right (contralateral)
somatopy of primary motor cortex?
neurons grouped into functional groups for muscle groups
motor homunculus:
fine motor units have _ areas devoted in somatopy
large motor units have _ area devoted in somatopy
larger
smaller
supplementary motor area:
motor maps for _
efferent signals to _
posture
limbs and trunk
premotor association area:
motor maps for _
_ of motor information
_ of volunatry movement
- movement of larger limbs
- processing of integrating and interpreting
- anticipation and planning
lesion to primary motor cortex would result in:
paralysis/weakness of contralateral side
lesion to motor association area would result in:
apraxia - can’t do something they know how to do like walk, brush hair
primary sensory cortex is located in _ lobe, on _ gyrus
parietal, postcentral
afferent information from right side of body travels ascending spinal cord tract to _ primary sensory cortex
left
the sensory homunculus is the same as the motor homunculus, larger areas get _ sensory innervation
more
cortical plasticity refers to how the body can _
change cortical representation
what is lateral inhibition?
inhibitory signals adjacent to area receiving sensory stimulation - contrast helps with tactile discrimination
sensory association area is adjacent to _
primary sensory corte in parietal lobe
sensory association area is responsible for _ of sensory information
interpretation
lesion to primary sensory cortex results in:
not a complete loss of sensory perception and deficit in awareness and localization of sensory stimuli (localizing where you were touched)
lesion to sensory association area results in:
tactile agnosia - inability to recognize what you tough
astereognosis - inability to recognize object in hand
primary visual cortex is loacted in _ lobe and lies above and below _ sulcus
occiputal lobe, calcarine
PVC: visual field information comes from _
optic radiations
right side of PVC receives _ visual field information
left
superior to calcarine sulcus receives _ visual field information
inferior
visual association area is located:
surrounding primary visual cortex
visual association area does what?
higher order processing that gives meaning and interpretation to what we are seeing
lesion to primary visual cortex would result in:
homonymous, contralateral defect (full or central) OR
bilateral altitudinal visual field defect
lesion to visual association area would result in:
visual agnosia - unable to recognize familiar objects, despite intact sight
and pursuit/saccadic deficits
primary auditory cortex is located in _ lobe on _ gyrus
deep temporal, superior temporal (heschel)
cochlear information is sent to _ medial geniculate nucleus of the thalamus
medial geniculate nucleus sends information to _
ipsilateral AND contralateral!!
primary auditory cortex
auditory association area is located? and responsible for?
adjacent to primary auditory cortex on temporal lobe, interpretation and meaning of sounds
Wernicke area is responsible for?
understanding language
lesion to primary auditory cortex would result in:
decreased perception of sound primarily in contralateral ear
lesion to auditory association area would result in:
acoustic verbal agnosia - “word deafness”, inability to interpret what is heard despite having intact hearing
primary sensory taste area?
insula
insula receives information from taste receptors in _
VPM of thalamus
primary olfactory sensory area is called?
entorhinal cortex
frontal association area is for:
planning and adaptation of behavior to social constructs
parietal association area is for:
attention and awareness
temporal association area is for:
recognition of things and situations around us
dorsal and lateral portions of frontal association area regulate _,
_ responses to stimuli
attention
motor
ventral and medial portions of frontal association area regulate _. motor expression to _ and _
emotions
emotions and behavior
frontal association areas has extensive innervation from _ systems of the brainstem
monoaminergic (dopamine, noradrenaline, seratonin)
the curious case of phineas gage:
rod went through what?
how was he affected?
frontal association area
no impulse control, antisocial, couldn’t control behavior
parietal association area:
integration of _ and _ area
crucial for _ _ _
somatic and visual
spatial/temporal attention
awareness of self
awareness of extrapersonal space
lesion to right parietal lobe would result in:
left spatial neglect (there is seldom left injury and right spatial inattention)
temporal association areas
fusiform gyrus - recognition of _ stimulus
lateral surface - recognition of _
visual
language
lesions to temporal lobe would result in:
agnosia and prosopagnosia (unable to recognize faces)
language is highly lateralized in the _ hemisphere
responsible for things like: _ _ _ _
non-dominate (usually right)
melody, rhythm, emotions, accents
dominate hemisphere (usually left) houses what 2 things?
broca’s area - expression of language
wernicke’s area - comprehension of language
broca area
_ gyrus of frontal lobe
_ of language
inferior frontal
production
wernicke area
_ gyrus of parietal/temporal regions
_ of language
superior temporal
comprehension and interpretation
aphasia vs dysarthria?
inability to communicate
vs damage to muscles
broca aphasia looks like?
(expressive or motor) - difficult producing, sparse and halting, grammer, frustration
wernicke aphasia looks like?
(receptive or sensory) - speak confidently, unaware that it doesn’t make sense
what does conduction aphasia look like? what is being affected?
arcuate fasciculus - if you say “repeat milk”, they may say “white liquid”
what is prognosis on conduction aphasia? why?
good due to cortical plasticity
modern model is putting less emphasis on _
lateralization
more interplay in senses, arcuate fasciculus has a diminished role
