MUSCLE PHYSIOLOGY

Detailed explanation-1: -Voltage-gated sodium channels play an important role in action potentials. If enough channels open when there is a change in the cell’s membrane potential, a small but significant number of Na+ ions will move into the cell down their electrochemical gradient, further depolarizing the cell.

Detailed explanation-2: -depolarization: Also called the rising phase, when positively charged sodium ions (Na+) suddenly rush through open voltage-gated sodium channels into a neuron.

Detailed explanation-3: -Once the sodium channels open, the neuron completely depolarizes to a membrane potential of about +40 mV. Action potentials are considered an “all-or nothing” event, in that, once the threshold potential is reached, the neuron always completely depolarizes.

Detailed explanation-4: -The rapid depolarization or the upstroke of the neuronal action potential occurs as a result of the opening of the voltage-gated sodium channels.