Atrioventricular (AV): Pertaining to the atria (the upper chambers of the heart) and the ventricles (the lower chambers of the heart).
The AV node is an electrical relay station between the atria and the ventricles. Electrical signals from the atria must pass through the AV node to reach the ventricles. The AV node is a major element in the cardiac conduction system that generates electrical impulses within the heart, conducts them throughout the muscle of the heart, stimulates the heart to contract and pump blood, and so controls the heart rate.
- Atrioventricular node
Atrioventricular node: The electrical relay station between the upper and lower chambers of the heart. Abbreviated AV node. Electrical signals from the atria must pass through the AV node to reach the ventricles. The AV node, which controls the heart rate, is one of the major elements in the cardiac conduction system. The AV node […]
Atrium: An entry chamber. On both sides of the heart, the atrium is the chamber that leads to the ventricle.
- Atrophic vaginitis
Atrophic vaginitis: Thinning of the lining (endothelium) of the vagina due to decreased production of estrogen. Atrophic vaginitis may occur with menopause.
Atrophy: A wasting away or diminution. Muscle atrophy is a decrease in muscle mass, often due to extended immobility.
Atropine: A drug, made from the belladonna plant, that is administered via injection, eye drops, or in oral form to relax muscles by inhibiting nerve responses.