nerve impulse

n.
A wave of physical and chemical excitation along a nerve fiber in response to a stimulus, accompanied by a transient change in electric potential in the membrane of the fiber.

Nerve impulses are electrical signals, known technically as action potentials, which transmit information along nerve fibres.

See action potentials.

n

A wave of excitation along a nerve fiber initiated by a stimulus; accompanied by chemical and electrical changes at the surface of the nerve fiber and followed by a transient refractory period during which further stimulation has no effect.

The electrical signal conducted along a neurone. It is the means by which information is transmitted in the nervous system from one neurone to another, or from a neurone to an effector organ (e.g. a group of muscle fibres). A nerve impulse takes the form of a wave of depolarisation, which passes along a nerve fibre. During its passage, the resting potential of the neurone is reversed and becomes an action potential. A nerve impulse in a single neurone obeys the all-or-none law.