The human heart is about the size of an adult's closed fist, but the size varies according to an individual's age, health and size. The heart weighs 7 to 15 ounces.
The aorta, the large artery that carries blood away from the heart, is about the same diameter as a garden hose. A heart beats about 100,000 times each day, sending an individual's entire 6-quart blood supply through the body three times each minute. This means that an individual's blood travels about 12,000 miles a day. The amount of effort required to squeeze a tennis ball is about the same amount of force the heart uses when it pumps.