Question

During the conduction of nerve impulse, the action potential is the result of movement of
A. $N{a^ + }$ from intracellular fluid to extracellular fluid
B. $N{a^ + }$ from extracellular fluid to intracellular fluid
C. $N{a^ + }$ towards both directions
D. None of the above

Answer 1

Action potential is the shift in electrical potential that occurs during the passage of a nerve impulse through the plasma membrane. Here, movement of sodium ions occurs in a particular direction, i.e. from the presynaptic cleft to the postsynaptic cleft.

Complete answer: In order to produce a nerve impulse or action potential, a nerve impulse, i.e. the electrical signal travels through the dendrites. The motion of ions in and out of the cell is the explanation of the action potential. It exclusively contains ions of sodium and potassium. They are transferred by sodium and potassium channels and sodium-potassium pumps in and out of the cell.
Because of the presence of active and electronic potential along the conductors, nerve impulse conduction occurs. Via a synapse, the transmission of signals internally between the cells is accomplished. Owing to the action of the $N{a^ + }/{K^ + }$ pumps, the polarised neuron is less permeable to the $N{a^ + }$ ions relative to the ${K^ + }$ when at rest. The threshold stimulus activates the sodium voltage-gated channels, as a result of which the $N{a^ + }$ ions pass from the extracellular fluid to the axon's intracellular fluid. This triggers membrane depolarization and the impulse is produced. In a comparable depolarization wave, this impulse travels down the axon.
So, the correct answer is option B.

Note: The electrical synapse is used in escape reflexes, in the heart and in the vertebrate retina. They are primarily used if a need for quick response and timing is crucial. When the action potential enters the stage of such a synapse, the ionic currents pass through the two cell membranes.