The velocity of a nerve impulse is greater in:

$A$: Presence of myelin sheath increases the rate of conduction of nerve impulse.
$R$: Ionic channels are absent in the area covered by myelin sheath; therefore,depolarization occurs only at the nodes of Ranvier,resulting in saltatory or jumping conduction.

During the transmission of a nerve impulse,which of the following events occurs?

An action potential in a nerve fiber is generated when the outer surface is positive and the inner surface is negative,and the membrane potential is reversed because...

Chronaxie is defined as:

In the resting stage of a neuron,the concentration gradient allows the diffusion of which ions?