Rest potential of a cell equals —80 mV. At what stage of action potential did the membrane potential equal +30 mV?

Answer options

1. After depolarization
2. -
3. Reverse polarization
4. Depolarization
5. After hyperpolarization

Explanation

During the rising phase (depolarization), once the membrane potential becomes positive, the membrane potential continues to depolarize (overshoot) until the peak of the action potential is reached at about +40 or +30 millivolts (mV). This phenomenon is also called reverse polarization.