The Atrium

The atrium is the upper chamber of the heart that receives blood coming from the body and lungs. The right atrium receives oxygen-poor blood from the body and pumps it into the right ventricle, which then sends it to the lungs for oxygen. The left atrium receives oxygen-rich blood from the lungs and passes it to the left ventricle, which pumps it to the rest of the body. The atria act as holding chambers, ensuring smooth blood flow into the lower chambers, and play a crucial role in maintaining efficient circulation.