Fourth Grade
Worksheets
Muscles
Your muscles keep your body moving. You use them to run, jump, walk, and lift things. You have more than six hundred muscles in your body. You have muscles everywhere, from your head to your toes. Some of your muscles help you to do the things that you want to do. You only use them when you need them to help you do something. Some of your muscles are hard at work all the time. You use them without even thinking about it. You might not even know that they are there.
There are three kinds of muscles in your body: cardiac muscle, skeletal muscle, and smooth muscle. Cardiac muscle is only found in one place in your body: your heart. Your heart is one big piece of muscle. It is always working; you don't even have to think about it. Skeletal muscle is what you probably think about when someone says the word muscle. Skeletal muscles work with your bones to give you the ability to move. These muscles only work when you want them to. You wouldn't want your leg muscles to be working while you are sitting in class. You would need them at the soccer field, though! There .....
