Chambers of the heart

The heart has four chambers: two upper chambers called atria and two lower chambers called ventricles. The right atrium receives oxygen-poor blood from the body and passes it to the right ventricle, which pumps it to the lungs for oxygen. The left atrium receives oxygen-rich blood from the lungs and sends it to the left ventricle, which then pumps it out to the rest of the body. This organized chamber structure ensures efficient blood flow, oxygen delivery, and removal of waste, supporting vital body functions.