Phases Of Action Potential
Polarization is the property applying to transverse waves that specify the geometrical orientation of the oscillations. Phases of action potential gauge your understanding of the different aspects of polarization. Take up the challenge and all the best.
Questions and Answers
- 1.
Rapid Depolarization - sodium(Na) ions flooding into the cell
Explanation
During the rapid depolarization phase (Phase 0) of an action potential, the correct answer states that sodium (Na) ions flood into the cell. This is because during Phase 0, the cell membrane rapidly becomes more positive as sodium channels open and allow sodium ions to rush into the cell. This influx of positive ions causes the membrane potential to rapidly depolarize, leading to the initiation of an action potential.Rate this question:
- 2.
Early Repolarization - The influx of sodium slows and the cell begins to repolarize.
- 3.
Plateau Phase (Repolarization) - Slow inward movement of calcium and outward movement of potassium
Explanation
Phase 2 of the cardiac action potential is known as the plateau phase. During this phase, there is a slow inward movement of calcium ions and an outward movement of potassium ions. This balance between calcium and potassium ions helps to maintain the depolarized state of the cell membrane, prolonging the action potential and allowing for sustained contraction of the cardiac muscle. This phase is important for the efficient pumping of blood by the heart.Rate this question:
- 4.
Rapid Repolarization - the end of sodium and calcium inflow and the rapid outward of potassium
Explanation
Phase 3 of cardiac action potential is characterized by rapid repolarization, which refers to the end of sodium and calcium inflow and the rapid outward movement of potassium ions. During this phase, the potassium channels open, allowing potassium ions to move out of the cell, which leads to the restoration of the cell's resting membrane potential. This repolarization prepares the cell for the next action potential and allows for proper cardiac rhythm and function.Rate this question:
- 5.
Absolute Refractory Period n-
- 6.
Relative Refractory Period - the cell can be excited to produce an action potential but only by a stimulus that is much stronger than normal
- 7.
Resting membrane potential - large permeable to potassium with the net loss of intracellular potassium
Explanation
In phase 4 of the cardiac action potential, the resting membrane potential is maintained. This is achieved by having a large permeability to potassium ions, which allows for the net loss of intracellular potassium. This loss of positive charge contributes to the negative resting membrane potential.Rate this question:
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Mar 22, 2023Quiz Edited by
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Sep 13, 2013Quiz Created by
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