GENERAL HISTOLOGY

Detailed explanation-1: -As K+ starts to leave the cell, taking a positive charge with it, the membrane potential begins to move back toward its resting voltage. This is called repolarization, meaning that the membrane voltage moves back toward the −70 mV value of the resting membrane potential.

Detailed explanation-2: -Repolarization (K+ efflux) Potassium channels open just as the sodium channels are closing. At this point the net current flow is reversed as potassium ions rush out of the cell, driving the membrane potential back towards the potassium equilibrium potential of –90 mV.

Detailed explanation-3: -There is an ion channel that allows for the ions to pass through the membrane only when that specific ion channel is open. Thus, when the ion channel opens, the ion moves down its concentration gradient from high to low, in this case for K+ from the inside (intracellular region) to the outside (extracellular region).