The third book in the popular elementary anatomy series God's Wondrous Machine, focuses on the heart, blood, and blood vessels that make up the body's circulatory system. Understanding the mechanics of this system in transporting nutrients, blood, chemicals, and more to cells within the body is key to understanding how it helps fight disease as well as maintain a properly balanced temperature. Readers learn how the deliberate design of their bodies enables it to function as it should, just as God meant for it to.