Class 11 NEET Biology Neural Control and Coordination

During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has first negative charge, due to the high concentration of potassium ions inside high concentration of sodium outside. This state is known as resting phase and the potential is known as rest potential. The nerve cells are stimulated by nerve signals the voltage-gated sodium channels reverse the membrane polarity which makes the inner side of the membrane positive while outer turns negative. The potential generated at this phase is known as the action potential. As the action potential reaches its maximum value it again causes the reversal of membrane potential which by closing the sodium channels and opening the potassium channels. This state of the neuron is known as repolarization.