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  2. Cardiac conduction system - Wikipedia

    en.wikipedia.org/wiki/Cardiac_conduction_system

    An impulse (action potential) that originates from the SA node at a relative rate of 60–100 bpm is known as a normal sinus rhythm. If SA nodal impulses occur at a rate less than 60 bpm, the heart rhythm is known as sinus bradycardia. If SA nodal impulses occur at a rate exceeding 100 bpm, the consequent rapid heart rate is sinus tachycardia ...

  3. Cardiac excitation-contraction coupling - Wikipedia

    en.wikipedia.org/wiki/Cardiac_excitation...

    This rate can be altered, however, by nerves that work to either increase heart rate (sympathetic nerves) or decrease it (parasympathetic nerves), as the body's oxygen demands change. Ultimately, muscle contraction revolves around a charged atom (ion) , calcium (Ca 2+ ) , [ 3 ] which is responsible for converting the electrical energy of the ...

  4. Atrioventricular node - Wikipedia

    en.wikipedia.org/wiki/Atrioventricular_node

    The blood supply of the AV node is from the atrioventricular nodal branch.The origin of this artery is most commonly (80–90% of hearts) a branch of the right coronary artery, with the remainder originating from the left circumflex artery.

  5. Bundle of His - Wikipedia

    en.wikipedia.org/wiki/Bundle_of_His

    The bundle of His (BH) [1]: 58 or His bundle (HB) [1]: 232 (/ h ɪ s / "hiss" [2]) is a collection of heart muscle cells specialized for electrical conduction.As part of the electrical conduction system of the heart, it transmits the electrical impulses from the atrioventricular node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the ...

  6. Cardiac pacemaker - Wikipedia

    en.wikipedia.org/wiki/Cardiac_pacemaker

    It employs pacemaker cells that produce electrical impulses, known as cardiac action potentials, which control the rate of contraction of the cardiac muscle, that is, the heart rate. In most humans, these cells are concentrated in the sinoatrial (SA) node, the primary pacemaker, which regulates the heart’s sinus rhythm.

  7. Cardiac physiology - Wikipedia

    en.wikipedia.org/wiki/Cardiac_physiology

    Regardless of the pathway, as the impulse reaches the atrioventricular septum, the connective tissue of the cardiac skeleton prevents the impulse from spreading into the myocardial cells in the ventricles except at the atrioventricular node. [1] The electrical event, the wave of depolarization, is the trigger for muscular contraction.

  8. File:Heart diagram-en.svg - Wikipedia

    en.wikipedia.org/wiki/File:Heart_diagram-en.svg

    English: Heart diagram with labels in English. Blue components indicate de-oxygenated blood pathways and red components indicate oxygenated blood pathways. Blue components indicate de-oxygenated blood pathways and red components indicate oxygenated blood pathways.

  9. Cardiac cycle - Wikipedia

    en.wikipedia.org/wiki/Cardiac_cycle

    In a healthy heart all activities and rests during each individual cardiac cycle, or heartbeat, are initiated and orchestrated by signals of the heart's electrical conduction system, which is the "wiring" of the heart that carries electrical impulses throughout the body of cardiomyocytes, the specialized muscle cells of the heart. [1] [2] These ...