An action potential is __________.

• A. a brief neutralization of the charges on sodium and potassium ions
• B. a sudden increase in speed by the sodium-potassium pump
• C. a sudden reversal of the sodium-potassium pump
• D. described by none of the listed responses
• E. a traveling wave of depolarization in the neuron membrane

Answer: (E)

Verified step by step guidance

1. Understand the concept of an action potential: An action potential is a rapid change in the electrical charge across a neuron's membrane, which allows the neuron to transmit a signal.
2. Recognize the role of ions: During an action potential, sodium ( <math xmlns="http://www.w3.org/1998/Math/MathML"> <msub> <mrow> <mi>Na</mi> </mrow> <mrow> <mo>+</mo> </mrow> </msub> </math> ) and potassium ( <math xmlns="http://www.w3.org/1998/Math/MathML"> <msub> <mrow> <mi>K</mi> </mrow> <mrow> <mo>+</mo> </mrow> </msub> </math> ) ions play crucial roles in changing the membrane potential.
3. Depolarization process: During depolarization, sodium channels open, allowing <math xmlns="http://www.w3.org/1998/Math/MathML"> <msub> <mrow> <mi>Na</mi> </mrow> <mrow> <mo>+</mo> </mrow> </msub> </math> ions to rush into the neuron, reversing the membrane potential.
4. Repolarization process: After depolarization, potassium channels open, allowing <math xmlns="http://www.w3.org/1998/Math/MathML"> <msub> <mrow> <mi>K</mi> </mrow> <mrow> <mo>+</mo> </mrow> </msub> </math> ions to flow out, restoring the negative charge inside the neuron.
5. Identify the correct description: The action potential is best described as a traveling wave of depolarization along the neuron membrane, which is the correct answer to the problem.