How It Works
The heart is a muscular organ that pumps blood to all parts of the body. The normal heart is about the size of your fist and lies in the middle of the chest, slightly to the left. It is protected by the breastbone and rib cage and is surrounded on either side by the lungs.
Your heart functions as a two-sided pump. The right side of the heart receives blood from all of the veins in the body and pumps it to the lungs. There, the blood loses carbon dioxide and picks up oxygen. The left side of the heart then receives oxygenated blood from the lungs and pumps it out to the entire body. A complex electrical system coordinates each heart beat.
There are four chambers in the heart, two upper chambers called the atria, and two bottom chambers called the ventricles. The atria's job is to fill the ventricle which then pumps blood to either the lungs or the body. The chambers are separated by valves which open and close with each heart beat. This opening and closing action keeps the blood flowing forward.
