Gray Matter
Gray matter is mostly neuron cell bodies and non-neuron brain cells called glial cells. These cells are not surrounded by white myelin. That is the reason they are gray. Gray matter is used for computation, thinking, memory storage, and more. Gray matter is also known as substantia grisea (sub-stan´shah grĭs′ē-ə, grĭz′-)
White Matter
White matter is tissue found in the brain. It contains nerve fibers. Some of the nerve fibers are covered by myelin, a type of fat. That's the reason they are white. White matter allows parts of the brain to communicate with each other. White matter is also known as substantia alba (sub-stan´shah ăl′bə)
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