Major Sulci and Areas of Cortex

Question 1

Where is the central suclus?

Answer 1

Begins behind the midpoint of the hemisphere and extends downwards just before it reaches the lateral sulcus

Question 2

What is the paracentral lobule?

Answer 2

A U-shaped gyrus surrounding the medial extension of the central sulcus which contains the representations of the lower limb within the primary motor and somatic sensory areas of the cortex which, on the lateral surface, occupy the pre-central and post-central gyri respectively

Question 3

What is the cingulate sulcus?

Answer 3

A long sulcus that separates the cingulate gyrus which runs above the corpus callosum from the rest of the hemisphere

Question 4

Where is the parieto-occipital sulcus?

Answer 4

It lies mainly on the medial surface of the hemisphere where it forms a Y shape with the calcarine sulcus

Question 5

Where is the calcarine sulcus?

Answer 5

Roughly at a right angle to the parieto-occipital sulcus, it rubs posteriorly to reach the occipital pole.

The primary visual cortex lies in the walls of the calcarine sulcus

Question 6

Where is the pre-occipital notch?

Answer 6

It lies posteriorly on the inferolateral border of the hemisphere vertically below and slightly in front of the point where the parieto-occipital sulcus reaches the supero-lateral margin

Question 7

What is the striae of Genari?

Answer 7

A white band in the primary visual cortex running parallel with the pial surface in the mid depth of the grey matter

Question 8

Compare the grey matter between the primary motor cortex and primary somatosensory cortex.

Answer 8

The grey matter in the primary motor cortex is over twice as thick as the grey matter in the somatosensory cortex whihc is sunstantially thinner