Nervous System: Controls the body and includes the brain and nerves.
Muscular System: Includes muscles which is what makes the body move.
Say you are in the street playing basketball. All of a sudden you hear a noise you recognize, a car coming closer. You then proceed to get out of the street. What just happened? Thank your nervous system and your muscular system. Let's break down what your body did to protect you...
1) Neurons detect a stimuli. In this case, your hearing detected the sound of your car which then was sent to your brain through the neurons.
2) Your brain interprets the information and sends instructions for a response. In this case, your brain realized a car is danger and sent out instructions to get out of the path of the car.
3) Your muscle move as a response. In this case, your legs in your muscles moved you out of harms way.
LETS RECAP THE STEPS
1) Neurons detect a stimulus
2) Your brain interprets the information and sends instructions for a response
3) Your muscles move as a response