ANATOMY

Detailed explanation-1: -The action potential is an explosion of electrical activity that is created by a depolarizing current. This means that some event (a stimulus) causes the resting potential to move toward 0 mV. When the depolarization reaches about-55 mV a neuron will fire an action potential. This is the threshold.

Detailed explanation-2: -The threshold is the value of the membrane potential which, if reached, leads to the all-or-nothing initiation of an action potential. The initial or rising phase of the action potential is called the depolarizing phase or the upstroke.

Detailed explanation-3: -An action potential is caused by either threshold or suprathreshold stimuli upon a neuron. It consists of three phases: depolarization, overshoot, and repolarization. An action potential propagates along the cell membrane of an axon until it reaches the terminal button.