In a neuron, when voltage-gated Na⁺ channels have just closed, which of the following is true? A) the membrane is less polarized than at rest B) the membrane is more polarized than at rest C) the membrane is polarized to the same degree as at rest D) the membrane is hyperpolarized E) none of the above are true

Question

Quizplus · Accepted Answer

When the voltage-gated Na+ channels have just closed, the neuron is in the refractory period, where the membrane potential is less polarized than at rest (-70mV). This is due to the fact that a large influx of positively charged sodium ions depolarizes the membrane potential during depolarization, but the closing of these channels prevents more influx of positively charged sodium, leading to a slight decrease in membrane potential.

In a Neuron, When Voltage-Gated Na+ Channels Have Just Closed

In a Neuron, When Voltage-Gated Na⁺ Channels Have Just Closed