Question

When a neuron is in resting state i.e., not conducting any impules, the axonal membrane is

• A. Comparatively more permeable to $K^{+}$ ions and nearly impermeable to $N{a}^{+}$ ions
• B. Comparatively more permeable to $N{a}^{+}$ ions and nearly impermeable to $K^{+}$ ions
• C. Equally permeable to both $N{a}^{+}$ and $K^{+}$ ions
• D. Impermeable to both $N{a}^{+}$ and $K^{+}$ ions

Answer 1

Answer: (A)

Comparatively more permeable to $K^{+}$ ions and nearly impermeable to $N{a}^{+}$ ions

There are electrical and concentration gradients in neurons that induce the sodium ions to enter the cell. The resting potential is maintained because the channels for sodium ions are closed. The membrane remains impermeable to sodium ions in the rest state. The membrane is more permeable to potassium passage. The potassium ions leak through the membrane at a greater rate than sodium enters. There is loss of positively charged ions from the inner part of the cell membrane. The inner part of the membrane carries a relatively more negative charge than the outer part of the cell membrane.

Thus, the correct answer is option A.