Atrium

The atrium is one of the four chambers of the heart, specifically the upper chambers. There are two atria: the right atrium receives deoxygenated blood from the body, while the left atrium receives oxygenated blood from the lungs. Each acts as a holding chamber that temporarily stores blood before passing it into the lower chambers (ventricles), which then pump it to the lungs or the rest of the body. The atria are essential for maintaining efficient blood flow and heart function, coordinating with other chambers to ensure proper circulation.