When a neuron is in resting state i.e., not conducting any impulse, the axonal membrane is
- comparatively more permeable to Na+ ions and nearly impermeable to K+ ions
- equally permeable to both Na+ and K+ ions
- impermeable to both Na+ and K+ ions
- comparatively more permeable to K+ ions and nearly impermeable to Na+ ions.
Answer
(4) comparatively more permeable to K+ ions and nearly impermeable to Na+ ions.
Solution
As per NCERT, when a neuron is not conducting any impulse, i.e., resting, the axonal membrane is comparatively more permeable to potassium ions (K+) and nearly impermeable to sodium ions (Na+).
⇒ This, together with the sodium-potassium pump (3 Na+ out for 2 K+ in), keeps the outer surface positive and the inner surface negative (resting potential).
Answer: (4)