How does the heart send blood through the body?

The heart pumps blood through the body by contracting its chambers in a coordinated manner. Oxygen-rich blood from the lungs enters the left atrium, then moves into the left ventricle, which contracts to push blood into the aorta and throughout the body. After delivering oxygen, the blood returns to the right atrium via the veins, then flows into the right ventricle, which pumps it to the lungs for oxygenation. This cycle of contraction and relaxation ensures continuous circulation of blood.