If the Permeability of a Resting Axon to Sodium Ion

Question

If the permeability of a resting axon to sodium ion increases,
A) the membrane potential will repolarize.
B) the membrane potential will hyperpolarize.
C) inward movement of sodium ion will increase.
D) outward movement of sodium ion will decrease.
E) inward movement of sodium will increase and the membrane will depolarize.

Accepted Answer

If the permeability of a resting axon to sodium ion increases, more sodium ions will enter the cell, causing depolarization of the membrane potential. Thus, inward movement of sodium ions will increase, and the membrane potential will become more positive towards the threshold for action potential initiation. Therefore, the best choice is E.