Join a tour of the muscular system, which includes over 600 muscles in your body. Learn about skeletal muscles that you can control, involuntary muscles like cardiac muscles in your heart, and smooth muscles in your digestive system in this illustrated narrative nonfiction book for elementary-age readers. Discover how muscles work with tendons and nerves to help you move. Includes tips for keeping your muscular system healthy and a glossary of important terms. Whimsical characters combined with informative diagrams will help kids understand the science of the human body.