Atrioventricular (AV) Node – Definition and Information

Definition of Atrioventricular Node Atrioventricular (AV) node is a cluster of electrical fibers in the heart that focuses and intensifies the electrical impulses the sinoatrial (sa) node initiates. The SA node, a cluster of specialized nerve fibers at the top of the right atrium near the superior vena cava, is the heart’s natural pacemaker. It generates a rhythmic electrical […]

Read More

Vein – what is and definition

Definition of Vein Vein – A blood vessel that carries blood to the heart. All veins except the pulmonary veins carry deoxygenated blood; the pulmonary veins return oxygenated blood to the heart from the lungs. Because veins lack the muscular structure and contractile capability of arteries, they have valves that keep blood moving only in one direction, toward the heart. The […]

Read More