The resting potential of about minus 70 millivolts across the membrane of a neurone is maintained mainly by
Correct answer: B. the sodium potassium pump, which moves three sodium ions out for every two potassium ions in
- A. the free diffusion of sodium into the cell
- B. the sodium potassium pump, which moves three sodium ions out for every two potassium ions in
- C. the opening of voltage gated sodium channels
- D. the release of neurotransmitter at the synapse
Explanation
The pump uses ATP to move more positive charge out than it brings in, and since the membrane is far more permeable to potassium, which leaks back out, the inside is left negative relative to the outside. Voltage gated sodium channels are shut at rest and open only when the threshold is reached, which is what produces the action potential rather than the resting state.
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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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