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  2. Depolarization - Wikipedia

    en.wikipedia.org/wiki/Depolarization

    In biology, depolarization or hypopolarization [1][2] is a change within a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge inside the cell compared to the outside. Depolarization is essential to the function of many cells, communication between cells, and the overall physiology of ...

  3. Refractory period (physiology) - Wikipedia

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

    The relative refractory period immediately follows the absolute. As voltage-gated potassium channels open to terminate the action potential by repolarizing the membrane, the potassium conductance of the membrane increases dramatically. K + ions moving out of the cell bring the membrane potential closer to the equilibrium potential for potassium ...

  4. Threshold potential - Wikipedia

    en.wikipedia.org/wiki/Threshold_potential

    In neuroscience, threshold potentials are necessary to regulate and propagate signaling in both the central nervous system (CNS) and the peripheral nervous system (PNS). Most often, the threshold potential is a membrane potential value between –50 and –55 mV, [1] but can vary based upon several factors. A neuron 's resting membrane ...

  5. QRS complex - Wikipedia

    en.wikipedia.org/wiki/QRS_complex

    QRS complex. Schematic representation of a normal sinus rhythm ECG wave. Diagram showing how the polarity of the QRS complex in leads I, II, and III can be used to estimate the heart's electrical axis in the frontal plane. The QRS complex is the combination of three of the graphical deflections seen on a typical electrocardiogram (ECG or EKG).

  6. Repolarization - Wikipedia

    en.wikipedia.org/wiki/Repolarization

    Repolarization is a stage of an action potential in which the cell experiences a decrease of voltage due to the efflux of potassium (K +) ions along its electrochemical gradient. This phase occurs after the cell reaches its highest voltage from depolarization. After repolarization, the cell hyperpolarizes as it reaches resting membrane ...

  7. Electrocardiography - Wikipedia

    en.wikipedia.org/wiki/Electrocardiography

    Use of real time monitoring of the heart in an intensive care unit in a German hospital (2015), the monitoring screen above the patient displaying an electrocardiogram and various values of parameters of the heart like heart rate and blood pressure. Electrocardiography is the process of producing an electrocardiogram (ECG or EKG[a]), a ...

  8. Afterhyperpolarization - Wikipedia

    en.wikipedia.org/wiki/Afterhyperpolarization

    Afterhyperpolarization, or AHP, is the hyperpolarizing phase of a neuron's action potential where the cell's membrane potential falls below the normal resting potential. This is also commonly referred to as an action potential's undershoot phase. AHPs have been segregated into "fast", "medium", and "slow" components that appear to have distinct ...

  9. Sinoatrial node - Wikipedia

    en.wikipedia.org/wiki/Sinoatrial_node

    This is the depolarization phase. When the membrane potential reaches the threshold potential (around -20 to -50 mV), the cell begins to rapidly depolarise (become more positive). [16] This is mainly due to the flow of Ca 2+ through L-type calcium channels, which are now fully open. During this stage, T-type calcium channels and HCN channels ...