During the propagation of a nerve impulse, the action potential results from the movement of?

Options

(a) K⁺ ions from extracellular fluid to intracellular fluid
(b) Na⁺ ions from intracellular fluid to extracellular fluid
(c) K⁺ ions from intracellular fluid to extracellular fluid
(d) Na⁺ ions from extracellular fluid to intracellular fluid

Correct Answer:

Na⁺ ions from extracellular fluid to intracellular fluid

Explanation:

Total sum of physio-electrochemical changes that takes place along the length of nerve fibre is known as nerve impulse. Change in potential due to stimulation of nerve fibre is called action potential. During propagation of nerve impulse, Na⁺ enters inside so(+ve) change is formed inside the membrane. K⁺ ions come out.