The absolute refractory period refers to a period during the action potential. This is the time during which another stimulus given to the neuron (no matter how strong) will not lead to a second action potential. The absolute refractory period starts immediately after the initiation of the action potential and lasts until after the peak of the action potential. Following this period, the relative refractory period begins.

Relative refractory period

Neuronal Action Potential - Refractory Periods

See absolute refractory period and relative refractory period.

Absolute refractory period
Relative refractory period

Neuronal Action Potential - Refractory Periods

The relative refractory period refers to a period during the action potential. This is the time during which a stronger than normal stimulus is needed in order to elicit an action potential. The relative refractory period immediately follows the absolute refractory period.

Absolute refractory period

Neuronal Action Potential - Refractory Periods