How Does a Healthy Heart Work?
By John T. Russo The Heart’s Circulatory System The heart is a fist-sized organ that weighs approximately one pound. It is a pump that circulates blood through the body. In fact, the heart pumps about 5 quarts of blood every minute or 1,800 gallons of blood every day. Arteries are the blood vessels that carry blood enriched with oxygen and nutrients to all parts of the body. Veins are the blood vessels that carry blood depleted of oxygen and nutrients back to the heart and lungs. Blood brings oxygen and nutrients to the organs and tissues as well as waste from the body’s cells. Waste products are removed as they filter through the kidneys, liver and lungs. The Heart’s Primary Function: Pumping Blood Blood is pumped through the four chambers of the heart. The upper chambers are the right and left atria. The lower chambers are the right and left ventricles. Four valves control the one-way flow of blood through the heart. Changes in pressure occur as the heart contracts; the valves open a
