Biology of the heart

[Gregory]

The heart and blood vessels constitute the cardiovascular (circulatory) system. The heart pumps the blood to the lungs so it can pick up oxygen and then pumps oxygen-rich blood to the body. The blood circulating in this system delivers oxygen and nutrients to the tissues of the body and removes waste products (such as carbon dioxide) from the tissues.
The heart, a hollow muscular organ, is located in the center of the chest. The heart has two sides, right and left. The right and left sides of the heart each have

Atrium: Upper chamber that collects blood and pumps it to the lower chamber
Ventricle: Lower chamber, which pumps blood out of the heart

To ensure that blood flows in only one direction, each ventricle has an