The heart carries oxygen-rich blood to our cells every second of our lives, and we don't even have to do much to keep this muscular organ moving. Incredibly, it only takes about 60 seconds to pump blood to every cell in the entire body! This fun fact and many more are found in this informative volume. Readers will learn about the different chambers of the heart, the path of blood through it, and how it works with blood vessels. Supportive illustrations, vivid photographs, and essential vocabulary make this a must-read introduction to the circulatory system.