Question

During a relative refractory period:

a. the action potential cannot be initiated.
b. a resting potential exists.
c. the cell membrane is impermeable to Na+ and K+.
d. the action potential can be initiated with a strong stimulus.

Answer 1

The correct statement for what happens during a relative refractory period is that an action potential can be initiated, but it requires a stronger stimulus than usual.

Step-by-step explanation:

During a relative refractory period, the correct statement is that the action potential can be initiated with a strong stimulus. This is due to the repolarization phase where voltage-gated K+ channels remain open, allowing K+ to exit the cell, and voltage-gated Na+ channels are in the process of returning to their resting state. Despite the high outflow of K+, an exceptionally strong stimulus can overcome this and depolarize the membrane to threshold, thus initiating another action potential.