Human Anatomy Part 2 - K. A. Diubenko, A. K. Kolomiitsev, Yu. B. Chaikovskyi 2008

Special Part
Nervous system, systema nervosum - Special Part
Pallium - Functional areas of the cerebral cortex

The Cerebral Cortex acts as a receptive Structure where nerve impulses originating in the receptor apparatus are projected as if onto a screen. Afferent fibers reach all areas of the cortex, while efferent fibers, traveling in the opposite direction, project to the subcortical nuclei, the motor nuclei of the Brainstem, and the Spinal Cord.

The Study of the cytoarchitectonics of the cerebral cortex expanded rapidly at the beginning of the 20th century. Pioneering work in this field was conducted by Campbell (1905), E. Smith (1907), K. Brodmann (1907-1909), and O. and C. Vogt (1919-1920), who mapped the topography of cytoarchitectonic cortical areas. K. Brodmann described 52 cytoarchitectonic areas, while the Vogts (O. and C. Vogt) identified 150 regions.

Based on architectonic features, The surface of the cerebral hemispheres is divided into zones (zonae), regions (regiones), and areas (areae). I. N. Filimonov and S. A. Sarkisov (Brain Research Institute of the RAMS, 1954) created detailed maps of the cytoarchitectonic areas of the human cerebral cortex. According to their data, the following cytoarchitectonic regions are distinguished, with their surface areas expressed as a percentage of the total hemispheric surface:

- occipital - 12;

- inferior parietal - 7.7;

- superior parietal - 8.4;

- postcentral - 5.4;

- precentral - 9.3;

- frontal - 23.5;

- temporal - 23.5;

- insular - 1.8;

- limbic - 4.0.

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Fig. 154 A, B. Cytoarchitectonic areas of the cerebral cortex (According to the Brain Research Institute of the RAMS).

A - medial surface; B - superolateral surface

The regions listed above are further divided into cytoarchitectonic areas, of which there are about 200 in the cortex (Fig. 154 A, B). Each area, In addition to its name, has its own number: 1, 2, 3, 4, 5, and so on. The areas are divided into three groups:

1) primary areas - the cortical ends (core zones) of sensory analyzers, where primary information is concentrated;

2) secondary areas - the peripheral zones of sensory analyzers, where the Processing (interpretation) of information takes place;

3) tertiary areas - the overlap zones of sensory analyzers, where motor programs (the Goals and Objectives of behavior) are formulated.

Functional areas of the cerebral cortex are divided into sensory, motor, and association areas. The sensory area decodes sensory impulses, the motor area controls Muscle movements, and the association area is responsible for emotional and cognitive activities.