After an action potential, the voltage-gated sodium channels close then
a. sodium ions diffuse into the axons
b. potassium ions flow out of the axon
c. the membrane potentials become positive
d. neurotransmitters cross the cell membrane
Everything return to normal/rest. 2 K+ flows into the cell and 3 Na+ ions flow outside the cell, both against their concentration gradient.
The correct answer is b. potassium ions flow out of the axon.
Explanation: After an action potential, when the voltage-gated sodium channels close, the voltage-gated potassium channels open. These channels allow potassium ions (K+) to flow out of the axon, returning the membrane potential back to its resting state. This process is known as repolarization.
To determine the correct answer, you need to understand the sequence of events during an action potential and how the different ion channels behave. Understanding the basic principles of neuronal physiology will help you deduce that the movement of potassium ions out of the axon is the right choice.
So, in this case, revise the concept of action potentials, specifically focusing on the events occurring after the voltage-gated sodium channels close and the role of the voltage-gated potassium channels in repolarization.