"Did you know that the largest bone in the human body is the femur? In adults, the skeleton makes up 15 percent of the body's weight. Discover more fascinating facts in How the Human Body Works - The Skeletal System. This series guides readers through the fascinating inner workings of the human body. The human body contains several complex systems that work closely together to support life and allow the body to function properly. Each book explores the characteristics and interactions of these systems, their makeup, and their importance."--