Cortical organisation and function

Question 1

What is the cerebral cortex and where is it found

Answer 1

Part of the brain. It covers the entire surface of the brain.
Together with deep nuclei it contains grey matter ( neuron cell bodies)

Highly folded with gyri ( bits that stuck out) and sulci ( bits that fold in) . A fissure is a type of sulci that separates the hemispheres

The cerebral cortex is organised into lobes

Remember different parts of the brain can interact with each other and share roles !

Question 2

How is the cerebral cortex organised microscopically

Answer 2

Into layers ( from 1-6 with 1 being the most superficial ) and columns

Question 3

What is cytoarchitecture and how can we classify the brain using it?
Bonus: who identified these regions

Answer 3

Cytoarchitecture is when the brain is separated into sections ( 52 of them) and divided to show cell size , spacing and packing density and layers. Often many areas shown related to function ( ie primary motor complex is at 4 and primary somatosensory complex is at 1,2 ,3)

Bonus: founded by Brodmann

see docs for pictures

Question 4

What are the 4 lobes of the cerebral cortex

Answer 4

Frontal , parietal , occipital , temporal

Question 5

What separates the frontal and parietal lobes?

Answer 5

Central sulci

Question 6

what separates the frontal and parietal lobes from the temporal one

Answer 6

Lateral fissure

Question 7

What is the role of the frontal lobe

Answer 7

regulates and initiates motor function , responsible for language, cognitive functions ( executive functions ie planning) , attention and memory

Question 8

What is the role of the parietal lobe

Answer 8

Sensation ie pain and touch , sensory aspects of language ( ie speech ) , spatial orientation and self perception ( where you are related to other things)

Question 9

Role of occipital lobe

Answer 9

Process visual information

Question 10

Role of temporal lobe

Answer 10

Process auditory information , emotions and memories

Question 11

Where do you find the limbic lobe

Answer 11

Deep in the brain, under cerebral cortex see diagram

Question 12

what structures are found in the limbic lobe and what are their roles?

Answer 12

Amygdala - detection of fear
Hippocampus - learning and memory
Mamillary body - long term memory
Cingulate gyrus - emotion and behaviour, motivation and reward

Question 13

Where is the insular cortex found

Answer 13

deep within lateral fissure

Question 14

Role of insular cortex

Answer 14

Visceral sensations ( sensations within the body) , autonomic control ( involuntary processes ie breathing) . interception ( understanding sensations from own body) , auditory processing , visual - vestibular integration ( aka sight and sound)

Question 15

What is grey matter made of

Answer 15

neuronal cell bodies and glial cells

Question 16

what is white matter made of

Answer 16

myelinated neuronal axons arranged in tracts

Question 17

What do white matter tracts connect

Answer 17

connect cortical areas ( connect areas of the cerebellum –> the parts under the cerebral cortex)

Remember different parts of the brain can interact with each other and share roles !

Question 18

What are the 3 types of fibres found in white matter tracts and what do they connect

Answer 18

1) Association fibres connecting areas within the same hemisphere
2) Commissural fibres connect homologous structures in left + right hemispheres
3) Projection fibres connect cortex with lower brain structures ie thalamus , brain stem , spinal cord

Note remember that both effect fibres leading away from the cortex and afferent fibres are projection fibres)

Question 19

Name 2 types of association fibres and give examples

Answer 19

1) Short fibres
2) Long fibres –> Superior longitudinal fasciculus connecting frontal and occipital lobes , Arcuate fasciculus connecting frontal an temporal lobes , Inferior longitudinal fasciculus connecting temporal and occipital lobes , Uncinate fasciculus connecting anterior frontal and temporal lobes

Question 20

Name 2 examples of commissural fibres

Answer 20

Corpus callosum

Anterior commissure

Question 21

Where are projection fibres found

Answer 21

Connecting the deeper brain to cortex projection fibres radiate and form corona raidata ( containing both afferent and efferent fibres . Remember afferent = towards cortex

Fibres converge through internal capsule between thalamus and basal ganglia

Question 22

How do we test function of cortices

Answer 22

Look at how brain responds in healthy induvial , then look at lesioned patients, surgery

Question 23

what is the function and organisation of 1ary cortices

Answer 23

Predictable function , organised topographically with symmetry between L and R

Question 24

what is the function and organisation of 2ary cortices

Answer 24

less predictable function , not organised topographically , L+R symmetry weak or absent