Myelination enhances the speed of action potential propagation.
The difference between myelinated and unmyelinated axons are in the propagation of action potential. In unmyelinated axons, the action potential travels continuously through the axons. On the other hand, among the myelinated nerve fibres, transmembrane currents can only occur at the nodes of Ranvier where the axonal membrane is exposed, so the excitation of the axonal membrane jumps from node to node. This propagation is called saltatory conduction and this movement of depolarization wave is much faster than in unmyelinated fibres.
