Through engaging text and full-color photos, readers learn that there are 600 muscles in the human body and that there are three different types of muscles, cardiac, smooth, and skeletal. Other topics discussed include tendons, cardiac muscle, and smooth muscles, which make up the walls of blood vessels, the stomach, and intestines and are found in the body's hollow organs. The book explains that cardiac and smooth muscle are involuntary muscles, while skeletal muscles are voluntary. Readers discover that every muscle has its own name, including flexors, extensors, abductors, and adductors. Readers also learn that the trapezius and gluteus maximus muscles are examples of muscles that are named for their size, shape, or location. Muscular diseases and the ways to keep muscles healthy, including exercise and a healthy diet are also highlighted. Detailed diagrams, medical models, phonetics, glossary, and index enhance the text.