Answer to Question #107283 in Human Anatomy and Physiology for Jose

Question

In addition to providing structural support and protection for the axon of a neuron, what other very important function is served by the presence of a myelin sheath?

Answer 1

Another very important function of myelin sheath formation by Schwann cells is to ensure efficient conduction of action potentials via electrical insulation. In between two Schwann cells are small areas where the axon is not myelinated, called the nodes of Ranvier, which enable the fast propagation of action potentials from node to node (salutatory conduction).

Myelination enables fast propagation of action potentials along the axon, through the formation of the node of Ranvier and the electrical isolation that it provides along the internodes, forcing action potentials to jump from one node to the next. This is thought to save energy because it limits the regeneration of action potentials, which is a highly energy-demanding process to the nodes of Ranvier.