An electric system transmits signals throughout the heart to control its pumping. The electrical s...
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An electric system transmits signals throughout the heart to control its pumping. The electrical signal begins in the sinoatrial or SA node. Located in the upper portion of the right, upper chamber, or atrium, it is known as the heart's natural pacemaker. The electrical signal passes down to the ventricles, the lower chambers of the heart via the atrioventricular or AV node. This controls the signals so the atria contract before the ventricles. Pathways carry the signal throughout the muscles of the ventricle so that they contract at the same time to pump blood to the lungs and through the body.