Myelin sheath question?

Question

why are myelin sheaths important to the transmission of signals along the axon?

Answer 1

The myelin sheath provides two benefits.

First, it increases the speed of transmission of the action potential down the axon.  The action potential jumps between gaps in the sheath by a process called saltatory conduction.

Second, it decreases the metabolic needs of the neuron by reducing the total amount of ion exchange that happens during an action potential.  That is, the current flow is only in the myelin gaps, not the entire length of the axon.