Читать книгу The Handy Psychology Answer Book - Lisa J. Cohen - Страница 297

Axons are coated by a fatty sheath known as myelin that speeds up the rate that the action potential travels down the axon. Because myelinated axons are white in appearance, brain tissue made up of these fibers is called white matter. In contrast, gray matter refers to brain tissue made up of dendrites and cell bodies (as well as glial cells and capillaries). The surface of the cortex is composed of gray matter.