action potential

action potential

noun

Definition of ACTION POTENTIAL

: a momentary reversal in electrical potential across a plasma membrane (as of a neuron or muscle fiber) that occurs when a cell has been activated by a stimulus

First Known Use of ACTION POTENTIAL

1926

action potential

noun    (Medical Dictionary)

Medical Definition of ACTION POTENTIAL

: a momentary reversal in the potential difference across a plasma membrane (as of a nerve cell or muscle fiber) that occurs when a cell has been activated by a stimulus—called also spike potential; compare resting potential; see afterpotential, generator potential, prepotential

action potential

noun    (Concise Encyclopedia)

Brief (about one-thousandth of a second) reversal of electric polarization of the membrane of a nerve or muscle cell. Stimulation of the cell by certain chemicals or by sensory receptor cells causes depolarization of the membrane, permitting an impulse to move along the nerve fibre (in nerve cells) or causing the cell to contract (in muscle cells).