Saltatory conduction is observed in which of the following?

The conduction of a nerve impulse is ....

Assertion $(A)$: The axonal membrane of the neuron is more permeable to sodium ion $(Na^+)$ and nearly impermeable to potassium $(K^+)$.
Reason $(R)$: In a resting state,a neuron does not conduct any impulse.

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

$A$ nerve impulse is generated in a nerve fiber when the membrane becomes more permeable to:

When a stimulus is applied to the membrane of a neuron,it causes a rapid influx of