*In less than a minute, your heart is able to pump blood to every cell in your body.
*The human heart is about the size of a fist.
*During an average lifetime, the human heart will beat more than 2.5 billion times.
*The heart weighs less than one pound (roughly the same as two apples).
*The human heart beats roughly 35 million times a year.
*Your rib cage protects your heart.
*The "thump-thump" of a heartbeat is the sound made by the four valves of the heart closing.
*Prolonged lack of sleep can cause irregular jumping heartbeats called premature ventricular contractions (PVCs).
*Squeeze a tennis ball tightly. That's how hard the beating heart works to pump blood.