Muscular System (a True Book: Your Amazing Body)

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.