Question

An action potential in the nerve fibre is produced when positive and negative changes on the outside and the inside of the axon membrane are reversed because

• A. more potassium ions enter the axon as compared to sodium ions leaving it.
• B. more sodium ions enter the axon as compared to potassium ions leaving it.
• C. all potassium ions leave the axon.
• D. all sodium ions enter the axon.

Answer 1

The correct option is B

more sodium ions enter the axon as compared to potassium ions leaving it.

When a nerve fibre is stimulated its membrane become more permeable to sodium ions.