PATHOLOGY

Detailed explanation-1: -As an action potential (nerve impulse) travels down an axon there is a change in electric polarity across the membrane of the axon. In response to a signal from another neuron, sodium-(Na+) and potassium-(K+)–gated ion channels open and close as the membrane reaches its threshold potential.

Detailed explanation-2: -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.