The brain has four regions: the cerebrum, the diencephalon, the brainstem, and the cerebellum. The cerebral hemispheres contain the greatest mass of brain tissue. Each hemisphere is subdivided into frontal, parietal, temporal, and occipital lobes.
The brain is a vast network of interconnecting neurons (nerve cells). These consist of cell bodies and their axons—single long fibers that conduct impulses to other parts of the nervous system.
Brain tissue may be gray or white. Gray matter consists of aggregations of neuronal cell bodies. It rims the surfaces of the cerebral hemispheres, forming the cerebral cortex. White matter consists of neuronal axons that are coated with myelin. The myelin sheaths, which create the white color, allow nerve impulses to travel more rapidly.
Was this article helpful?