Refractory Period, Electrophysiological

**Definition:** The period of time following the triggering of an ACTION POTENTIAL when the CELL MEMBRANE has changed to an unexcitable state and is gradually restored to the resting (excitable) state. During the absolute refractory period no other stimulus can trigger a response. This is followed by the relative refractory period during which the cell gradually becomes more excitable and the stronger impulse that is required to illicit a response gradually lessens to that required during the resting state.

**Tree numbers:** - G07.265.753.770 - G07.265.760 - G11.561.601.770 - G11.561.785