During the relative refractory period of an action potential, a larger than normal stimulus is needed to cause another action potential. This is due to the fact that ___________.
A) the membrane is now impermeable to all ions
B) the sodium potassium pump will stop working during relative refractory
C) the voltage gated potassium ion channels remain open long enough to hyperpolarize the axon membrane
D) the inactivation gates on voltage gated sodium ion channels are closed

Question

Quizplus · Accepted Answer

During the relative refractory period, the voltage gated potassium ion channels remain open longer than usual, which causes hyperpolarization of the membrane potential. This makes it more difficult for the neuron to reach threshold and generate another action potential. The sodium potassium pump continues to work during this period, and the inactivation gates on voltage gated sodium ion channels are open again, allowing sodium ions to enter the cell if a strong enough stimulus is applied. However, membrane permeability is not affected during the relative refractory period.

During the Relative Refractory Period of an Action Potential, a Larger