How does myelination affect nerve impulse conduction velocity?

Nerve impulses are propagated in the form of action potentials, involving the rapid depolarisation of the nerve cell membrane from  -70mV to +30mV, before repolarisation occurs returning the membrane potential to -70mV. This cycle of depolarisation and repolarisation is propagated along the nerve cell as an electrical signal. Myelinated axons are covered in a protective, lipid rich myelin sheath produced by Schwann cells. This insulates regions of the nerve cell, so they cannot depolarise. Regions that lack myelin are called “nodes of Ranvier” and these become the only areas where action potentials can form, resulting in “jumping” of the nerve impulse from node to node. This is called saltatory conduction. Saltatory conduction results in faster nerve impulse conduction velocity, as the action potentials can “jump” along the neuron.