The heart is a hollow organ with tough, muscular walls located under the breast bone (sternum). The heart is about the size of a fist and contracts rhythmically to pump blood to the lungs and to the rest of the body.The heart is divided into two sides by a vertical wall (septum). Each side of the heart again divides into upper and lower chambers. Valves inside these chambers prevent blood from flowing backwards.
The heart receives deoxygenated blood from all parts of the body, and pumps this blood to the lungs. Here, the lungs supply the blood with oxygen. After receiving this oxygen-rich blood, the heart pumps it back to the body through the aorta (the largest blood vessel leaving the left side of the heart). Because the heart is a muscle doing continuous work, it needs its own oxygen-rich blood supply. This blood is supplied by the coronary arteries which branch off from the aorta.
You can find out more about heart transplantation at our hospital.