Myelin forms the so-called white matter in the nervous system and constitutes 50 percent of the weight of the brain. It is also an important component of the spinal cord, and of nerves in other parts of the body.
There are also axons in the nervous system which are not wrapped in myelin. These constitute what is known as gray matter. Unmyelinated axons transmit messages in the nervous system up to 100 times slower than their myelinated cousins.
In multiple sclerosis the myelin sheaths of myelinated nerve fibers degenerate, leading to impaired sensory nerve and motor nerve function, and in most cases some degree of disability.
Related category• BIOCHEMISTRY
Home • About • Copyright © The Worlds of David Darling • Encyclopedia of Alternative Energy • Contact