During phase 3 of the action potential, (chose one)

Question

During phase 3 of the action potential, (chose one)

A. chemical gated ion channels
B. voltage gated Na + channels
C. voltage gated K+ channels

are open and (chose one)
A. Na+ and K+
B. Na+ only
C. K+ only

is/are diffusing (chose one)
A. out of
B. into
C. both into and out of

Answer 1

C. voltage gated K+ channels are open and

C. K+ only is diffusing

C. both into and out of the cell during phase 3 of the action potential.

Answer 2

During phase 3 of the action potential, voltage-gated K+ channels are open and K+ is diffusing out of the cell. Specifically, the correct choices are:

C. voltage-gated K+ channels
C. K+ only
A. out of

Answer 3

During phase 3 of the action potential, the correct answer is:

C. voltage gated K+ channels

are open and the correct answer is:

A. K+ only

is diffusing.

Explanation:
During the action potential, there are different phases that involve the opening and closing of ion channels in the neuron's membrane. In phase 3, also known as the repolarization phase, the membrane potential starts to return to its resting state.

In this phase, the voltage gated K+ channels open. These channels allow the flow of K+ ions out of the neuron. Since the intracellular concentration of K+ is higher than the extracellular concentration, K+ ions move down their concentration gradient and diffuse out of the cell.

The reason behind the movement of K+ out of the cell is the relatively positive charge inside the neuron due to the previous influx of Na+ ions during phase 0 and phase 1 of the action potential. As the K+ ions move out, they contribute to the repolarization of the neuron's membrane potential.

So, during phase 3, the voltage gated K+ channels are open, and K+ ions are diffusing out of the cell. These processes are essential for restoring the neuron to its resting state and preparing it for the next action potential.