Definition

The brain is a large mass of soft nervous tissue made up of both neurons and supporting glial cells lying within the cranium of the skull. The brain contains both gray and white matter. Gray matter is primarily nerve cell bodies, whereas white matter contains myelinated nerve cell processes, giving it a white appearance. White matter is mostly found in the cortex (shell) of the cerebral hemispheres. The brain has a highly complex appearance, with convolutions referred to as gyri and valleys referred to as sulci. These convolutions create a greater surface area within the same size skull.

Description

Central nervous system

The central nervous system is made up of the brain and spinal cord. The major divisions of the human brain are the brainstem,