The Muscular System

Muscles are the parts of your body that help you move. You have muscles all over, from your head to your toes. Some muscles you control, and some work on their own. Without muscles, you could not walk, smile, or even blink.

Types of Muscles

There are three kinds of muscles in your body. Skeletal muscles pull on your bones to help you move. Smooth muscles work inside your stomach and other organs. Cardiac muscle makes up your heart and pumps blood.

An old colorful drawing showing all the muscles in the body.
An old colorful drawing showing all the muscles in the body. (Bouglé, Julien. / Wikimedia Commons)

How Muscles Work

Muscles work by getting shorter, which is called contracting. When a muscle pulls on a bone, your body moves. Muscles often work in pairs. One pulls while the other relaxes.

Fun Facts

  • You have over 600 muscles in your body.
  • It takes 17 muscles to smile and 43 to frown.
  • The strongest muscle for its size is in your jaw.

Did You Know?

Your tongue is made of eight muscles working together. That is why it can move in so many ways.