Here's how it works:

* Brain and Spinal Cord: The brain and spinal cord form the central nervous system. They receive information from the body and send out instructions.

* Nerves: Nerves are bundles of fibers that carry signals throughout the body. These signals are electrical impulses.

* Motor Neurons: Motor neurons are a type of nerve cell that carry signals from the brain and spinal cord to muscles and glands. These signals tell the muscles to contract or relax, and the glands to secrete their substances.

Example: When you decide to lift your arm, your brain sends a signal down the spinal cord and out to the motor neurons that control the muscles in your arm. These motor neurons activate the muscles, causing your arm to move.

In summary: The nervous system acts like a complex communication network, allowing your brain to control your body's movements and functions.