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

Options

A. Nearly impermeable to potassium ions `(K^(+))`
B. Impermeable to positively charged proteins present in the axoplasm.
C. Comparatively more permeable to `K^(+)`
D. Completely permeable to sodium ions `(Na^(+))`

Answer

**Step-by-Step Solution:**

1. **Understanding the Resting State of a Neuron:**
- When a neuron is in a resting state, it is not conducting any nerve impulses. This state is referred to as a polarized state.

2. **Ion Distribution:**
- In this resting state, the distribution of ions is crucial. There is a higher concentration of potassium ions (K⁺) inside the neuron and a higher concentration of sodium ions (Na⁺) outside the neuron.

3. **Role of Sodium-Potassium Pumps:**
- The sodium-potassium pumps actively maintain this ion gradient by using energy (ATP). They pump out 3 sodium ions for every 2 potassium ions pumped in, which helps keep the inside of the neuron negatively charged relative to the outside.

4. **Resting Membrane Potential (RMP):**
- The difference in charge across the axonal membrane creates a resting membrane potential (RMP) of approximately -70 mV. This means the inside of the neuron is more negative compared to the outside.

5. **Membrane Permeability:**
- At rest, the axonal membrane is more permeable to potassium ions than to sodium ions. This is because the potassium channels are more open, allowing K⁺ to move out of the neuron, while sodium channels are closed.

6. **Conclusion:**
- Therefore, when a neuron is in its resting state, the axonal membrane is comparatively more permeable to potassium ions.

**Final Answer:**
The axonal membrane is comparatively more permeable to potassium ions.

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