Question

The membrane potential of a resting neuron is:

• A. -20 and -60 millivolts
• B. -30 and -80 millivolts
• C. -20 and -80 millivolts
• D. -60 and -80 millivolts

Hint:

For a resting neuron, remember the number \textbf{-70 mV} as the classic textbook value. This will help you quickly identify the correct range, which is -60 to -80 mV. The negative sign is crucial; it means the inside of the cell is negative compared to the outside.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The resting membrane potential is the electrical potential difference across the plasma membrane of a nerve cell when it is not stimulated or excited. It is a fundamental property of neurons that allows them to transmit signals.
Step 2: Detailed Explanation:


The resting membrane potential is established and maintained by the differential permeability of the membrane to various ions, primarily potassium (K\(^+\)) and sodium (Na\(^+\)), and the action of the Na\(^+\)/K\(^+\) pump.

In a resting state, the neuron's membrane is much more permeable to K\(^+\) than to Na\(^+\), due to the presence of open K\(^+\) "leak" channels.

K\(^+\) ions, which are concentrated inside the cell, diffuse out down their concentration gradient, leaving behind unpaired negative charges (anions like proteins) inside the cell.

This movement of positive charge out of the cell makes the inside of the membrane negative relative to the outside.

The typical value for the resting membrane potential in most neurons ranges from -60 to -80 millivolts (mV), with a commonly cited average value of -70 mV.

The other ranges provided are not representative of a typical neuron's resting potential.

Step 3: Final Answer:
The membrane potential of a resting neuron is typically in the range of -60 to -80 millivolts.