During the refractory period a neurone
Correct answer: A. cannot be stimulated again, which keeps the impulse travelling in one direction
- 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.
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About Neurons and Nerve Impulse
Neurons receive and transmit information through dendrites, the cell body and axons. The topic explains resting potential, depolarization, repolarization, refractory periods and saltatory conduction, followed by synaptic transmission through neurotransmitters. An action potential is distinct from the graded potential produced at a receptor.
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