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  2. Repolarization - Wikipedia

    en.wikipedia.org/wiki/Repolarization

    The channels are active during repolarization as well as during the atrial diastole phase when the current undergoes hyperpolarization. [14] Specifically, these channels are activated when Ca 2+ binds to calmodulin (CaM) because the N-lobe of CaM interacts with the channel's S4/S5 linker to induce conformational change. [ 15 ]

  3. Action potential - Wikipedia

    en.wikipedia.org/wiki/Action_potential

    The process proceeds explosively until all of the available ion channels are open, resulting in a large upswing in the membrane potential. The rapid influx of sodium ions causes the polarity of the plasma membrane to reverse, and the ion channels then rapidly inactivate.

  4. Cardiac action potential - Wikipedia

    en.wikipedia.org/wiki/Cardiac_action_potential

    During phase 3 (the "rapid repolarization" phase) of the action potential, the L-type Ca 2+ channels close, while the slow delayed rectifier (I Ks) K + channels remain open as more potassium leak channels open. This ensures a net outward positive current, corresponding to negative change in membrane potential, thus allowing more types of K ...

  5. Refractory period (physiology) - Wikipedia

    en.wikipedia.org/wiki/Refractory_period_(physiology)

    During repolarization, voltage-gated sodium ion channels inactivate (different from the closed state) due to the now-depolarized membrane, and voltage-gated potassium channels activate (open). Both the inactivation of the sodium ion channels and the opening of the potassium ion channels act to repolarize the cell's membrane potential back to ...

  6. Afterhyperpolarization - Wikipedia

    en.wikipedia.org/wiki/Afterhyperpolarization

    During single action potentials, transient depolarization of the membrane opens more voltage-gated K + channels than are open in the resting state, many of which do not close immediately when the membrane returns to its normal resting voltage. This can lead to an "undershoot" of the membrane potential to values that are more polarized ...

  7. Ventricular action potential - Wikipedia

    en.wikipedia.org/wiki/Ventricular_action_potential

    The delayed opening of more Ca 2+-activated K + channels, which are activated by build-up of Ca 2+ in the sarcoplasm, while the Ca 2+ channels close, ends the plateau. This leads to repolarization. The depolarization of the membrane allows calcium channels to open as well. As sodium channels close calcium provides current to maintain the ...

  8. Cardiac physiology - Wikipedia

    en.wikipedia.org/wiki/Cardiac_physiology

    At this point, the calcium ion channels close and potassium channels open, allowing outflux of K + and resulting in repolarization. When the membrane potential reaches approximately −60 mV, the K + channels close and Na + channels open, and the prepotential phase begins again. This process gives the autorhythmicity to cardiac muscle. [1]

  9. Sinoatrial node - Wikipedia

    en.wikipedia.org/wiki/Sinoatrial_node

    This phase is the repolarization phase. This occurs due to the inactivation of L-type calcium channels (preventing the movement of Ca 2+ into the cell) and the activation of potassium channels, which allows the flow of K + out of the cell, making the membrane potential more negative. [17]