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Basics: Difference between revisions
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→The ECG represents the sum of the action potentials of millions of cardiomyocytes
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During the depolarization, sodium ions stream into the cell. Subsequently, the calcium ions stream into the cell. These calcium ions cause the actual muscular contraction. Finally the potassium ions stream out of the cell. During repolarization the ion concentration returns to its precontraction state. On the ECG, an action potential wave coming toward the electrode is shown as a positive (upwards) signal. Here the ECG electrode is represented as an eye. | During the depolarization, sodium ions stream into the cell. Subsequently, the calcium ions stream into the cell. These calcium ions cause the actual muscular contraction. Finally the potassium ions stream out of the cell. During repolarization the ion concentration returns to its precontraction state. On the ECG, an action potential wave coming toward the electrode is shown as a positive (upwards) signal. Here the ECG electrode is represented as an eye. | ||
[[Image:Ion_currents_en.png|thumb|left|300px|Ion currents of the cardiomyocytes]] | [[Image:Ion_currents_en.png|thumb|left|300px|Ion currents of the cardiomyocytes]] | ||
[[Image:Hart_cells_en.png|thumb|right|300px|The heart consists of approximately 300 | [[Image:Hart_cells_en.png|thumb|right|300px|The heart consists of approximately 300 billion cells]] | ||
[[Image:cells_in_rest_en.png|thumb|right|300px|In rest the heart cells are negatively charged. Through the depolarization by surrounding cells they become positively charged and they contract.]] | [[Image:cells_in_rest_en.png|thumb|right|300px|In rest the heart cells are negatively charged. Through the depolarization by surrounding cells they become positively charged and they contract.]] | ||