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Definition of Node, AV

Node, AV:

AV node: The AV node (AV stands for atrioventricular) is an electrical relay station between the atria (the upper) and the ventricles (the lower chambers of the heart). Electrical signals from the atria must pass through the AV node to reach the ventricles.



The electrical signal generated by the SA node moves from cell to cell down through the heart until it reaches the AV node, a cluster of cells situated in the center of the heart between the atria and ventricles. The AV node serves as a gate (an "electrical relay station") that slows the electrical current before the signal is permitted to pass down through to the ventricles. This delay ensures that the atria have a chance to fully contract before the ventricles are stimulated. After passing the AV node, the electrical current travels to the ventricles along special fibers embedded in the walls of the lower part of the heart.


Source: MedTerms™ Medical Dictionary
Last Editorial Review: 8/28/2013

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