During the refractory period a neurone

  • A. cannot be stimulated again, which keeps the impulse travelling in one direction
  • B. conducts impulses at double speed
  • C. releases neurotransmitter continuously
  • D. reverses its resting potential permanently

Explanation

For a brief interval after an action potential the sodium channels are inactivated and cannot reopen, so the region just passed cannot fire again and the impulse can only move forwards. The same period also sets an upper limit on how many impulses a second an axon can carry, which limits how strong a sensation can be coded. The membrane returns fully to its resting state afterwards.

Related questions