The relative refractory period is caused by which of the following? Opening of v
ID: 3473626 • Letter: T
Question
The relative refractory period is caused by which of the following?
Opening of voltage-gated sodium channels
Opening of voltage-gated potassium channels
Inactivation of voltage-gated sodium channels
Inactivation of voltage-gated potassium channels
Opening of potassium leakage channels
a.Opening of voltage-gated sodium channels
b.Opening of voltage-gated potassium channels
c.Inactivation of voltage-gated sodium channels
d.Inactivation of voltage-gated potassium channels
e.Opening of potassium leakage channels
Explanation / Answer
answer is c.
After the absolute refractory period, Na+ channels begin to recover from inactivation and if strong enough stimuli are given to the neuron, it may respond again by generating action potentials. However, during this time, the stimuli given must be stronger than was originally needed when the neuron was at rest. This situation will continue until all Na+channels have come out of inactivation. The period during which a stronger than normal stimulus is needed in order to elicit an action potential is referred to as the relative refractory period (RRP). During the relative refractory period, there is continued K+flow out of the cell would tend to oppose any depolarization caused by opening of Na+channels that have recovered from inactivation.