The right atrium is one of the four chambers of the heart. It receives deoxygenated blood from the body through two large veins called the superior vena cava and inferior vena cava. This chamber plays a crucial role in the circulatory system by collecting blood that needs to be sent to the lungs for oxygenation. Once the right atrium fills with blood, it contracts to push the blood into the right ventricle. From there, the blood is pumped to the lungs via the pulmonary arteries to receive oxygen. The right atrium is essential for maintaining proper blood flow and oxygen levels in the body.