1. a fatty, whitish substance that forms a sheath around nerve fibers and speeds up the transmission of electrical signals in the nervous system
Usage: anatomy, neuroscience

Examples

• Myelin insulates nerve fibers much like plastic coating protects electrical wires.
• Damage to myelin can slow down nerve impulses and cause neurological problems.
• Multiple sclerosis is an autoimmune disease that attacks myelin in the brain and spinal cord.
• The myelin sheath allows neurons to transmit signals more quickly and efficiently.
• Myelin is produced by specialized cells called oligodendrocytes in the brain and spinal cord.
• Without myelin, nerve signals would travel much more slowly through the nervous system.