Muscles work by contracting and relaxing to move parts of your body.

1. Your brain sends a signal through your nerves to a muscle.

2. The muscle gets the message and contracts (gets shorter and tighter).

3. This pulls on bones (because muscles are attached to bones), which makes you move.

4. To stop the movement, the muscle relaxes and goes back to its normal shape.

There are 3 types of muscles:

Skeletal muscles (move your body parts, like arms and legs)

Smooth muscles (in your stomach, help move food)

Cardiac muscle (only in your heart, pumps blood .