ATRIOVENTRICULAR NODE Meaning and
Definition
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The atrioventricular (AV) node refers to a specialized bundle of nerve cells located in the lower chamber of the heart, known as the ventricles. It serves as a crucial electrical relay station, serving to regulate the coordination and timing of the heart's contractions.
Specifically, the AV node receives electrical impulses that originate in the upper chamber of the heart, called the atria. These impulses are generated by the sinoatrial (SA) node, a cluster of cells positioned in the wall of the right atrium. The SA node acts as the natural pacemaker of the heart, initiating the regular electrical signals that prompt the heart muscle to contract.
Once the electrical impulses from the SA node reach the AV node, it temporarily delays the conduction of these signals before transmitting them to the ventricles. This delay facilitates the proper filling of the ventricles with blood from the atria, ensuring optimal efficiency of the heart's pumping action.
The AV node then relays the electrical signals to the bundle of His, a specialized network of electrical fibers located within the walls of the ventricles. The bundle of His subsequently branches off into smaller fibers called Purkinje fibers, which then distribute the electrical impulses throughout the ventricles, causing them to contract in a coordinated manner.
In summary, the atrioventricular node is an essential component of the heart's electrical conduction system, acting as an intermediary between the atria and the ventricles, facilitating the synchronized contraction of the heart chambers and maintaining proper blood circulation.
Etymology of ATRIOVENTRICULAR NODE
The word "atrioventricular node" comes from Latin and Greek roots.
- "Atrio" derives from the Latin word "atrium", which means "entry hall" or "central room". In the context of the heart, the atrium refers to the two upper chambers where blood enters the heart.
- "Ventricular" comes from the Latin word "ventriculus", meaning "small belly" or "cavity". In the context of the heart, ventricular refers to the two lower chambers responsible for pumping blood out of the heart.
- "Node" comes from the Latin word "nodus", which means "knot" or "knob". In the context of the heart, the node refers to specialized tissues responsible for electrical signal conduction.
