Where does the blood in your heart start and end?

Blood in the heart starts in the right atrium, where deoxygenated blood from the body returns via the superior and inferior vena cavae. It then moves to the right ventricle, which pumps it to the lungs for oxygenation through the pulmonary arteries. After picking up oxygen, the blood returns to the heart's left atrium via the pulmonary veins, moves to the left ventricle, and is then pumped out to the body through the aorta. This cycle continues as blood circulates throughout the body and returns to the heart.