The Mighty Pump That Keeps You AliveThe heart is one of the most important organs in the human body. It is responsible for blood pumping, which carries oxygen and nutrients to different parts of the ...

Hold out your hand and make a fist. If you're a kid, your heart is about the same size as your fist, and if you're an adult, it's about the same size as two fists. Your heart beats about 100,000 ...