Describe the electrical events that occur during the rising and falling phase of an action potential

What will be an ideal response?


The rising phase of the action potential (depolarization) is due to a sodium ion influx induced by an explosive increase in sodium ion permeability at threshold. During this phase, voltage-gated sodium channels open and allow sodium influx. The falling phase (repolarization) is brought about by a potassium ion efflux caused by a marked increase in potassium ion permeability occurring simultaneously with an inactivation of sodium channels at the peak of the action potential. The outward potassium current is due to the delayed opening of voltage-gated potassium channels which are activated at threshold and then exhibit a delayed opening.

Anatomy & Physiology

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Anatomy & Physiology