Identify the point in time during an action potential when a positive feedback process is occurring in a neuron.
A)when the neuron is at rest
B)as the neuron is being depolarized and passes the threshold potential
C)after the peak depolarization of the action potential when it is rapidly repolarizing
D)during the undershoot phase when the neuron is slightly hyperpolarized relative to the resting potential
E)A positive feedback process is occurring at all the time points given.

Question

Quizplus · Accepted Answer

A positive feedback process occurs during the depolarization phase, specifically after the threshold potential is reached. This positive feedback is due to the opening of voltage-gated sodium channels, leading to a rapid influx of sodium ions, which further depolarizes the membrane and triggers the opening of more sodium channels. This process continues until the peak of the action potential is reached.

Identify the Point in Time During an Action Potential When