cerebral cortex

Question 1

cerebral cortex

Answer 1

cerebral cortex- outermost layer of cerebrum composed of gray matter

functions of cerebral cortex: process sensory info, voluntary movement emotional processing, memory, language, higher order processing

Question 2

cellular architecture

Answer 2

neocortex- cortex made up of 6 layers, comprises most of the human brain

cell composition- neocortical cells, pyramidal cells (primary output from cerebral cortex, most abundant cell type in cortex)

granule cell- mostly act as inhibitory interneurons

Glia- astrocytes, microglia, oligodendrocytes

Question 3

pyramidal neurons

Answer 3

excitatory (glutamatergic) neurons with many dendritic spines

Triangularly shaped cell body

Apical and basal dendrites

axon projects to cerebral white matter

Question 4

cortical lamination

Answer 4

neocortex has 6 layers of neurons:

1. molecular layer
2. external granular layer
3. external pyramidal layer
4. internal granular layer
5. internal pyramidal layer
6. polymorphic layer

Question 5

cellular arrangement of neocortex

Answer 5

layer 1: cell poor layer, input from other areas of cortex
layer 2: to other cortical areas in same hemisphere
layer 3: to other cortical areas in opposite hemisphere
layer 4: receives input from thalamus!
layer 5: large pyramidal neurons, project to brainstem, sp cd etc
Layer 6: sends output back to thalamus

Question 6

cellular arrangement

Answer 6

cellular arrangement: cortical neurons are grouped into columns according to specific preferred stimulus

columns with the same function are linked within and between hemispheres

brodmanns areas: thickness of each layer differs between regions, Brodmanns area- cortex classified into regions according to cytoarchitectural similarity by korbinian brodmann

Question 7

fiber types within cerebral cortex

Answer 7

commissural fibers, association fibers, projection fibers

association fibers: connect structures on same side of cerebrum

commissural fibers: go betwen the cerebral hemispheres

projection fibers: connect cerebrum to other parts of the CNS

Question 8

functional regions of cerebral cortex

Answer 8

primary motor areas: gives rise to corticospinal tract
primary sensory areas: receive information about one sense

Association areas: Unimodal (elaborate on function of primary area), Multimodal (combine information about multiple modalities)

Question 9

frontal lobe

Answer 9

M1 or 1’ motor cortex: voluntary movement, contralateral somatotopy, lesion: contralateral spastic paralysis

Premotor cortex: planning of motor movement, contains supplementary motor cortex and frontal eye field

Prefrontal cortex: multimodal association area for complex integration, executive function: control over other cortical areas, aspects of personality, cognition metacognition, into PFC relays through MD nucleus of thalamaus

Bocas area: typiccally on left side–> brocas aphasia if lesion on left, if non dominant (r side)–> difficulty expressing emotional aspects of languafe

Question 10

parietal lobe

Answer 10

1’ somatosensory cortex (S1)- touch and pain sensation from body and face, contralateral somatotopy, input from VPL/VPM of thalamus, lesion: contralateral loss of sensation

parietal association cortex: multimodal association area (integrate tactile, visual, auditory information) spatial awareness, input from LP and pulvinar of thalamus
Lesion: dominant side (alexia, agraphia, astereognosis), non-dominant side (spatial distortion, contralateral neglect)

Question 11

temporal lobe

Answer 11

1’ auditory cortex: discrete auditory information (tonotopic organization, input relayed through MGN of thalamus, lesion: hearing loss)

Auditory association area (A2): unimodal association are related to audition

Wernickes area: area for speech comprehension, typically on left side, lesions dominant: wernickes aphasia, non dominant: difficulty comprehending emotional aspects of language

Question 12

occipital lobe

Answer 12

1’ visual cortex: discrete visual information, visuotopic organization, input related through LGN of thalamus. One side contralateral hemianopia, upper/lower bank: contralateral superior/inferior quadrantanopia

visual association areas- distributed throughout occipital, parietal, and temporal cortices

Question 13

limbic lobe

Answer 13

1’ olfactory cortex- receives information regarding smell, uncus, info does not relay through thalamus before reaching 1’ olfactory cortex

Cingulate gyrus- process emotions and emotional aspects of pain

Parahippocampal gyrus- role in spatial memory

Question 14

insula

Answer 14

1’ gustatory cortex: receives taste info from VPM of thalamus, insula also processes visceral sensation and

Question 15

Cortical blood supply

Answer 15

ACA
MCA
PCA
blood from cortex drains into venous sinuses, drain into internal jugular vein