Your brain and nerves make up your nervous system. Your brain is the command center of your body. Your brain sends signals through your nerves. Some signals from your brain control your muscles. Suppose you want to walk across the street. Your brain sends signals that tell the muscles in your legs to move.
You do not have to think about some of the signals your brain sends out through your nerves. Your nervous system tells your heart to beat and your lungs to breathe even when you are sleeping.
Nerves also send signals back to your brain. Nerves tell your brain what your eyes see. They tell your brain when you stub your toe.
