An atrium is one of the two upper chambers in the heart that receives blood from the veins and pumps it into the lower chambers, known as ventricles. Each side of the heart has one atriumโthe left atrium receives oxygenated blood from the lungs, while the right atrium receives deoxygenated blood from the body.
Ventricle: A ventricle is one of the two lower chambers of the heart that receives blood from an atrium above and pumps it out to the body or lungs.
Cardiac Cycle: The cardiac cycle refers to the sequence of mechanical and electrical events that repeat with every heartbeat, involving both filling and ejection phases of both atria and ventricles.
Septum: The septum is a wall dividing two cavities or areas, such as the thick wall separating the left and right sides of the heart, including between atria and ventricles