Cerebral Cortex

Question 1

Cerebral cortex is the outermost layer of the cerebral hemispheres. It is composed of three parts:-

Answer 1

Archicortex - oldest part of the cortex, connects the limbic system to the cortex
Paleocortex - associated with the olfactory system
Neocortex - accounts for 90% of the cortex. The surface is folded to increase surface area. Grooves are called sulci and ridges are called gyri. There are four lobes (sections), frontal lobe, parietal lobe, temporal lobe, and occipital lobe.

The frontal lobe is separated posteriorly from the parietal lobe by the central sulcus (aka fissure of Rolando) and inferiorly from the temporal lobe by the lateral fissure (aka Sylvian fissure).

Question 2

Neocortex

Answer 2

The neocortex is the outermost part of the cerebral hemispheres. It is involved with higher functions, such as thought and language. It is divided into 6-7 layers.

Layer I - Molecular layer
Layer II - External granular layer
Layer III - External pyramidal layer
Layer IV - Internal granular layer
Layer V - Internal pyramidal
Layer VI - Multiform
There are two main cell types in the neocortex:-

Pyramidal cells
Non-pyramidal cells (granular/stellate cells). There are two types of non-pyramidal cell, one excitatory (glutamate), and one inhibitory (GABA).

The surface of the neocortex is divided up into separate areas. This was done by Brodmann and so each area is given a number (e.g. Brodmann’ area 17 is the primary visual cortex).