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

Options

A. `k^(+)` ions from intracellular fluid to extracellular fluid
B. `Na^(+)` ions from extracellular fluid to intracellular fluid
C. `K^(+)` ions from extracellular fluid to intracellular fluid
D. `Na^(+)` ions from intracellular fluid to extracellular fluid

Answer

B

Explanation

When a depolarizing graded potential or some other stimulus causes the membrane of the axon to depolarize to threshold. Voltage gated `Na^(+)` channels open rapidly. Both the electrical and chemical gradients favour inward movement of `Na^(+)` causes depolarizing phase of the action potential changes the membrane potential from – 55 mv to + 30 mv.