4. Neuroanatomy

Question 1

which structures make up the CNS and PNS

Answer 1

CNS = cerebrum, brainstem, cerebellum and spinal cord

PNS = cranial nerves III-XII and peripheral nerves

Question 2

which structures form the forebrain, midbrain and hindbrain

Answer 2

• forebrain = cerebrum + diencephalon (thalamus, hypothalamus and pituitary gland)
• midbrain = midbrain
• hindbrain = pons, medulla + cerebellum

Question 3

which structures form the brainstem and what is their general function

Answer 3

1. midbrain (mesencephalon): eye movements and reflex responses to sound and vision
2. pons: feeding (mastication pattern generator, CN Vc) and sleeping
3. medulla: cardiovascular and respiratory centres, major motor pathways via medullary pyramids

Question 4

define the terms gyrus, sulcus and fissure

Answer 4

Gyrus = ridge of cerebrum
Sulcus = groove separating adjacent gyri
Fissure = large split between adjacent areas of cerebrum, e.g. great longitudinal fissure between 2 hemispheres

Question 5

name the 4 main lobes of the brain and state their general function

Answer 5

1. frontal lobe: higher cognition, motor function, speech (primary motor cortex in pre-central gyrus)
2. parietal lobe: sensation, spatial awareness (primary somatosensory cortex in post-central gyrus)
3. temporal lobe: memory, smell, hearing (primary olfactory and auditory complexes)
4. occipital lobe: vision (primary visual cortex)

Question 6

what is the corpus callosum

Answer 6

white matter fibres connecting the 2 cerebral hemispheres, enabling communication

Question 7

what is contained in the brain ventricles and where else is this found in the CNS

Answer 7

CSF, also found in subarachnoid cisterns (beween pia and arachnoid)

Question 8

what is the function of the cerebellum

Answer 8

coordination and fine motor control