From the skin that covers us to the heart that pumps the blood, the human body is a complex machine whose parts must work together to keep us healthy and alive. Each title in new "The Human Body: How It Works" series investigates a different system or process of the human body, from organ systems to cells. Written by experts in human anatomy and accompanied by brand-new full-color photographs, illustrations, charts, and diagrams, these new titles thoroughly examine each system's role in keeping the human body moving.