Myelin is a white, fatty substance primarily made of proteins, cholesterol, and phospholipids. Myelin is critical to the functioning of the nervous system and is responsible for increasing the speed at which impulses travel from one neuron to another. It also assists with the regeneration of injured nerve fibers.
The myelin sheath that insulates axons in the central nervous system (CNS) is formed by oligodendroglia. The myelin that covers axons in the peripheral nervous system (PNS) is formed by Schwann cells.
