Question
Phases of action potential
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Answered by
GPT 3.5
There are four main phases of the action potential in a neuron:
1. Resting Phase: The neuron is at rest, with a resting membrane potential of around -70mV. At this stage, the sodium-potassium pump actively maintains the concentration gradients of sodium and potassium ions across the cell membrane.
2. Depolarization Phase: When a stimulus is detected, sodium channels open and sodium ions rush into the cell, causing the membrane potential to rapidly depolarize. This results in a temporary reversal of the membrane potential, known as the threshold potential.
3. Repolarization Phase: After reaching the peak of depolarization, potassium channels open and potassium ions flow out of the cell. This causes the membrane potential to repolarize, returning to its resting state.
4. Hyperpolarization Phase: In some cases, the membrane potential may briefly overshoot its resting state and become more negative than usual. This is known as hyperpolarization and occurs due to the prolonged opening of potassium channels. The sodium-potassium pump then works to restore the resting membrane potential.
Overall, the action potential allows for the rapid transmission of signals along neurons, enabling communication within the nervous system.
1. Resting Phase: The neuron is at rest, with a resting membrane potential of around -70mV. At this stage, the sodium-potassium pump actively maintains the concentration gradients of sodium and potassium ions across the cell membrane.
2. Depolarization Phase: When a stimulus is detected, sodium channels open and sodium ions rush into the cell, causing the membrane potential to rapidly depolarize. This results in a temporary reversal of the membrane potential, known as the threshold potential.
3. Repolarization Phase: After reaching the peak of depolarization, potassium channels open and potassium ions flow out of the cell. This causes the membrane potential to repolarize, returning to its resting state.
4. Hyperpolarization Phase: In some cases, the membrane potential may briefly overshoot its resting state and become more negative than usual. This is known as hyperpolarization and occurs due to the prolonged opening of potassium channels. The sodium-potassium pump then works to restore the resting membrane potential.
Overall, the action potential allows for the rapid transmission of signals along neurons, enabling communication within the nervous system.