Question

During nerve impulse transmission permeability of a membrane is greater for

• A. $N{a}^{+}$
• B. $K^{+}$
• C. Equal for both A and B
• D. $C{a}^{2+}$

Answer 1

Answer: (A)

$N{a}^{+}$

At resting stage, the membrane is almost impermeable to sodium and potassium ions. When an impulse is generated, then the resting potential changes into the action potential. There is a change in the permeability of sodium ions. The sodium-potassium pumps get opened and allow movement of two potassium and three sodium ions through the pumps. There is an influx of sodium ions which causes a change in the membrane potential.

So, the correct answer is option A.