What body system is the human heart part of?

The human heart is part of the circulatory system. This muscular organ continuously pumps blood through the heart, blood vessels, and lungs, delivering oxygen and nutrients while helping remove carbon dioxide and other waste products.

The heart has four chambers: the right and left atria on top and the right and left ventricles below. The right side sends oxygen-poor blood to the lungs, while the left side pumps oxygen-rich blood through the aorta to the rest of the body. Valves keep blood moving in the proper direction.

The circulatory system is sometimes called the cardiovascular system. “Cardiovascular” refers specifically to the heart and blood vessels, while the broader circulatory system is often discussed as including the pulmonary circulation between the heart and lungs and systemic circulation between the heart and the rest of the body.

A common mix-up is placing the heart in the respiratory system because it works closely with the lungs. The lungs oxygenate the blood, but the heart is the pump that circulates it. Its electrical conduction system coordinates each heartbeat, allowing circulation to continue throughout the body.