8.5—Saltatory conduction

In a myelinated axon, the sheath insulates the membrane between nodes of Ranvier. Depolarisation is regenerated at the nodes, so the impulse appears to jump along the axon by saltatory conduction.

The insulation reduces ion leakage and increases conduction speed compared with a non-myelinated axon, where the membrane is activated continuously.

Damage to myelin can slow or disrupt signalling even when the axon and its cell body remain present, because the normal node-to-node pattern is lost.

Saltatory conduction does not mean the impulse skips the cytoplasm entirely, and a nerve is a bundle of axons rather than one myelinated cell.