Many axons, especially the larger ones, are insulated with a myelin sheath. Write an essay on the importance of the myelin sheath, making sure to incorporate the following information:

? What kind of cells make up the myelin sheath?
? What does the myelin sheath look like?
? What are two purposes of the myelin sheath?
? What happens when a person experiences the loss of myelin?
What will be an ideal response?

Answer: A good answer will include the following key points.
? Myelin is a fatty sheath formed by glial cells.
? It occurs in segments along the axon and looks like a string of link sausages.
? Its key functions are to prevent signals in adjacent cells from interfering with each other and to speed up conduction of neural impulses.
? In individuals with multiple sclerosis, loss of myelin causes erratic nerve signals resulting in things like loss of sensation, muscle weakness or paralysis, lack of coordination, or vision problems.