The speed of an action potential, also known as the conduction velocity, generally depends on two things: 1.) The diameter of the axon, and 2.) The myelination of the axon. Axons that have larger diameters conduct impulses faster because depolarization is allowed to more rapidly spread throughout the interior of the cell. Axons that are myelinated also conduct impulses faster than axons that are unmyelinated. This is because myelin resists the flow of ionic currents, and so it channels the depolarization down the axon interior until it reaches a small gap in the cellular membrane that lacks myelin, where it can be regenerated. Therefore, myelination allows action potentials to "jump" between nodes along the axon (see "Saltatory Conduction").