Discover the main systems of our amazing human body with this new series of books!

Our muscular system covers our bodies from head to toe. It helps keep us upright and gives us the power to stand, sit, run, smile, and more. Did you know that your muscles make up one-third of your body weight? Or that your tongue is made up of eight separate muscles? Learn all this and more in Muscular System.

ABOUT THE SERIES:

The human body is a complex―and remarkable―machine. Digesting our food. Pumping our blood. Walking, running, and dancing. It takes our many body systems working together to keep us alive and living our lives to the fullest. This set of A True Books offers an in-depth look at our amazing bodies―one system at a time. Interesting information is presented in a fun, friendly way―and in the simplest terms possible―giving students a "behind-the-scenes" look at how their bodies work.