Question

Which of the following diagram illustrates the distribution of $N{a}^{+}$ and $K^{+}$ ions in a section of non-myelinated axon which is at resting potential?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

When a neuron is at resting potential, i.e., not conducting any impulse the axonal membrane is comparatively more permeable to K+ ions and nearly impermeable to Na+ ions.

Consequently the axoplasm inside the axon contains high concentration of K+ ions. In contrast, the fluid outside the axon has a high concentration of Na+ ions and thus forms a concentration gradient.

Thus, the correct answer is "option A"