Definition: A substance rich in fatty lipids and proteins that covers and protects nerves. Myelin is a layered tissue that "sheathes" the nerve fibers. The myelin sheath aids in the rapid and efficient transmission of impulses along the nerve cells. Myelin is present in both the central nervous system and the peripheral nervous system. Damaged myelin may lead to numerous health conditions, including multiple sclerosis.
Also Known As: myelin sheath