GENERAL HISTOLOGY

Detailed explanation-1: -As the sodium ions rush back into the cell, they add positive charge to the cell interior, and change the membrane potential from negative to positive. Once the interior of the cell becomes more positively charged, depolarization of the cell is complete, and the channels close again.

Detailed explanation-2: -The clinical implication is that in situations of sustained depolarization, the voltage-gated sodium channel will stop working, preventing the cells from becoming more and more positive. This mechanism is an important safeguard to ensure that unimpeded depolarization cannot occur.

Detailed explanation-3: -Once the action potential is triggered, the depolarization (2) of the neuron activates sodium channels, allowing sodium ions to pass through the cell membrane into the cell, resulting in a net positive charge in the neuron relative to the extracellular fluid.

Detailed explanation-4: -Depolarization is the first step in an action potential. In this step the voltage-gated sodium channels open due to an external stimulus. These channels permit rapid flow of sodium ions into the cell. This changes the polarity of the cell and causes the membrane potential to increase.