How a Healthy Heart Works
The heart is the most important muscle in your body. It is made up of four chambers: the right atrium, right ventricle, left atrium and left ventricle.
The right side of the heart receives blood that is low in oxygen from veins all over the body. It pumps this blood through the pulmonary arteries into the lungs where it becomes re-oxygenated.
The left side of the heart receives this oxygen-rich blood from the lungs. It pumps the blood through the aorta back out to the rest of the body through a complex network of arteries, arterioles and capillaries.
While blood is circulating through the body, it delivers oxygen and nutrients to the tissue through the capillaries, and at the same time, picks up carbon dioxide and other waste materials. The veins return the de-oxygenated blood to the heart and the cycle begins again.
How Your Heart Valves Work
Your heart has four valves that control the flow of blood to and from your heart: the tricuspid valve, pulmonic valve (also called pulmonary valve), mitral valve and aortic valve.
The heart's four valves function like one-way doors to keep blood flowing in one direction. The valves are made up of two or three strong flaps of tissue called leaflets. The leaflets open to allow blood to flow through the valve and close to prevent blood from flowing back into the heart chamber.
The opening and closing of the heart's four valves is controlled by blood pressure changes within each heart chamber. When blood flow is compromised, mild to severe symptoms such as fatigue, weakness, shortness of breath or chest pain can result.
Last Reviewed: January 19, 2010 2506