Muscular System

Some of your muscles keep your body moving. Your skeletal muscles work with your bones to run, jump, walk, and lift things. Some of your muscles help things inside your body move. They are hard at work all the time without you having to think about using them. Cardiac muscle, found only in your heart, pumps blood and keeps it moving through your body. Smooth muscle is found inside many of your internal organs. For instance, smooth muscles line the stomach and intestinal walls to help move food through the digestive system. This theme unit tells all about the muscular system.