A

David

Darling

nerve impulse

A nerve impulse is an electrical signal that travels along the axon of a neuron (nerve cell). Nerve impulses carry information throughout the nervous system. As an impulse passes, sodium and potassium ions flow into and out of the axon's membrane (see sodium-potassium pump), creating a voltage reduction called the action potential. Nerve impulses can travel at up to 150 meters (500 feet) per second.