Encyclopedia > Myelin

  Article Content

Myelin

Myelin is an electrically insulating fatty layer that surrounds the axons of many neurons, especially those in the peripheral nervous system. It is an outgrowth of glial cells: Schwann cells supply the myelin for peripheral neurons while oligodendrocytes[?] supply it to those of the central nervous system.

The main consequence of a myelin layer (a sheath) is an increase in the speed at which impulses propagate along the myelinated fiber. Along "unmyelinated" fibers impulses move continuously as waves, but in "myelinated" fibers they hop (or "propagate by saltation"). On the other hand, myelin reduces the capability of neurons to heal themselves.

If an axon's myelin degrades, due to a disease such as multiple sclerosis for example, conduction can be impaired or lost.



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
DB

... company of New Zealand. This is a disambiguation page; that is, one that just points to other pages that might otherwise have the same name. If you followed a link ...

 
 
 
This page was created in 26.5 ms