Muscles move everything in your body. They move your eyes, your tongue, and your legs. Muscles are made out of many stretchy, elastic cells and fibers. You have more than 600 muscles in your body. Your muscles make up half of the weight of your body.
Muscles work in pairs.
One muscle pulls the bone forward, and another muscle pulls the bone back. Your muscle pairs work very well together. Your muscles also help to hold your organs in place. Your muscles help your organs do their work. Your diaphragm muscle helps your lungs breathe.