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What causes the depolarization phase of an action potential?

What causes the depolarization phase of an action potential?

Depolarization is caused by a rapid rise in membrane potential opening of sodium channels in the cellular membrane, resulting in a large influx of sodium ions. Membrane Repolarization results from rapid sodium channel inactivation as well as a large efflux of potassium ions resulting from activated potassium channels.

What phase does depolarization occur?

Phase 0
Phase 0 is the phase of depolarization; Phase 1 through 3 is the phases during which repolarization occurs; Phase 4 is the resting phase with no spontaneous depolarization. During phase zero, the phase of rapid depolarization, voltage-gated Na+ channels open, resulting in a rapid influx of Na+ ions.

What causes the depolarization phase of an action potential quizlet?

The depolarization phase of an action potential results from the opening of which channels? Voltage gated sodium channels. when the voltage-gated Na+ channels open, Na+ rushes into the cell causing depolarization. You just studied 15 terms!

What are the four phases of an action potential?

Definition Steps Phases Refractory period Propagation of action potential Synapse Summary

What does phase 0 represent in action potential?

Phase 0. The influx of calcium ions (Ca 2+) through L-type calcium channels also constitutes a minor part of the depolarisation effect. The slope of phase 0 on the action potential waveform (see figure 2) represents the maximum rate of voltage change , of the cardiac action potential and is known as dV/dt max .

Does action potiential depolarize or repolarize?

Action potential in a neuron, showing depolarization , in which the cell’s internal charge becomes less negative (more positive), and repolarization, where the internal charge returns to a more negative value. Most cells in higher organisms maintain an internal environment that is negatively charged relative to the cell’s exterior.

What happens to the axon during repolarization?

When an action potential signal travels across the axon, it causes the cell to depolarize, or become more positively charged. After the signal ends, the cell goes through repolarization, where it returns to its original negative polarization.