Your heart is a vital organ, tirelessly pumping blood throughout your body whether you are resting, carrying out your daily activities, or exercising strenuously. It is the muscular powerhouse at the center of your circulatory system, and its healthy function keeps you alive, deliver-
ing nourishing blood to every cell of every tissue in your body.
The heart and the circulatory system together make up your cardio- vascular system, which accomplishes the complex function of distribut- ing oxygen and other nutrients to body cells, as well as carrying away carbon dioxide and other waste products of cellular function for elimi- nation. Your heart provides the pumping action and force to push your blood ?rst through the lungs to take on oxygen, and then out into the circulatory system. Your circulatory system ferries the blood out to body tissues via arteries, then back to the heart through veins. More than 60,000 miles of blood vessels are involved in this vast network.
The heart itself is about the size of a ?st and weighs less than a pound. To “put your hand over your heart,” you place it just to the left of your sternum, or breast bone, which is located in the center of your chest. You can usually feel your heart’s regular beat, because the right side of the roughly cone-shaped organ tilts closest to your chest wall at this point. Behind the heart are the lungs. These organs are well pro- tected within the bony structure of your chest cavity, with the spinal column and ribs behind them.