An adult has 206 bones in their body, but the skeletal system includes much more than these bones. It also includes cartilage, ligaments, and tendons, altogether making up about one-fifth of a human's total body weight. Your readers will learn about this incredible system that is the framework of their bodies. Eye-catching photographs correlate closely with engaging, accessible text, encouraging a deeper understanding of the key scientific concepts discussed. Concise fact boxes present additional information in separate, manageable sections.