Cerebral cortex (8.3)

Question 1

Identify and describe the lobes of the brain

Answer 1

Question 2

Describe the cerebral cortex in relation to the rest of the forebrain, brainstem and cerebellum

Answer 2

Cerebral cortex: The outer layer of the cerebrum. Composed of folded gray matter (neuronal bodies). Plays an important role in consciousness. Arranged into 3 layers, each with a differing number of cellular layers

• Neocortex: 6 layers
  
  • Only has 3 layers in the cerebellum
• Archicortex 4 layers
• Paleocortex: 3 layers

Question 3

Describe the neurons in the CNS and the consequences of damage

Key groups

Answer 3

Substantia nigra:

• Midbrain
• Dopaminergic neurones
• Damage → Parkinson’s

Raphe nucleus magnus

• Medulla
• Serotonergic neurones
• Damage/loss → depression

Locus coeruleus

• Pons
• Noradrenergic neurones
• Damage/loss → depression

Cholinergic

• Damage → Alzheimer’s

Glutaminergic

• Over stimulation → epilepsy, excitotoxic shock

GABAergic

Question 4

State the difference between grey and white matter

Answer 4

Gray matter: Located around the ‘exterior’ aspect of the cerebrum. Contains the cell bodies of neurons.

White matter: Located ‘centrally’. Contains the axons/processes of neurons.

Question 5

Explain the core functions of areas around the cortex

Answer 5

Question 6

Describe the homonculus for the motor and sensory cortices

Answer 6

Question 7

Explain how the cortices provide contralateral supply

Answer 7

Decussation of neuronal fibres from the cerebral hemispheres means that each hemisphere provides motor and sensory innervation to the contralateral musculature

Question 8

State the functional dominance of the left and right hemispheres

Answer 8

Question 9

State the effects of lesions to the cortex:

ACA, MCA, PCA, temporal, parietal, frontal, FEF, Broca’s, Wernicke’s

Answer 9

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For arterial lesions/occlusions refer to homunculus