Asked in Human Anatomy and Physiology
How does myelination effect nerve conduction velocity?
March 10, 2011 2:31AM
Myelination will speed the nerve conduction velocity considerably. Myelin is found in Schwann cells which encircle a given axon. It acts mainly as an insulator so that depolarization in one cell does not set off depolarizations in adjoining cells. When a neural membrane is depolarized, local currents are set up between positive and negative ions causing membrane conduction. In myelinated fibers, the local currents go from one internode (or node of Ranvier) in between two Schwann cells to the next internode. Thus we have "salutatory conduction" where a neural impulse actually jumps from one internode to the next without being conducted down the entire cell membrane.