Nervous System: Neuron, Synapse, Reflexes · Zoology

During the depolarization phase of an action potential, which of the following events occurs?

Voltage-gated $K^{+}$ channels open, and $K^{+}$ leaves the cell
The $Na^{+}/K^{+}$ pump stops working entirely
Voltage-gated $Na^{+}$ channels open, and $Na^{+}$ enters the cell
The membrane potential becomes more negative than the resting potential

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Correct answer: Voltage-gated $Na^{+}$ channels open, and $Na^{+}$ enters the cell

Depolarization is characterized by a rapid influx of sodium ions into the neuron. This occurs because the membrane potential reaches the threshold, causing voltage-gated $Na^{+}$ channels to open and move $Na^{+}$ down its electrochemical gradient.

Difficulty: Medium Question 2 of 20

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During the depolarization phase of an action potential, which of the following events occurs?

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