An action potential in a nerve fibre

A. False It occurs when the membrane potential is reduced to its threshold for firing.

B. True This leads to rapid depolarization towards the sodium equilibrium potential.

C. False Permeability to K+ increases and the resulting K+ efflux contributes to membrane repolarization.

D. True This depolarizes the adjacent axon and leads to propagation of the impulse.

E. False Because of the ‘all or none’ law, impulse configuration is independent of stimulus strength.