The Heart: Our Circulatory System

Join award-winning science writer Seymour Simon as he investigates one of the body’s most important organs: the heart.

Acclaimed science writer Seymour Simon brings you this indispensable guide that takes you through the heart, from atrium to capillary and back again.

By the time you finish reading these words, your heart may have beaten up to 50 times. As you walk, eat, and sleep, your heart continually pumps trillions of blood cells through thousands of miles of blood vessels inside your bo...