Answer the following question given this paragraph: 

A small child darts in front of your bike as you race down the street. You see the child and immediately react. You put on the brakes, steer away from the child, and yell out a warning, all in just a split second. How do you respond so quickly? Such rapid responses are controlled by your nervous system. The nervous system is a complex network of nervous tissue that carries electrical messages throughout the body. It includes the brain and spinal cord, the central nervous system , and nerves that run throughout the body, the peripheral nervous system (see Figure below ). To understand how nervous messages can travel so quickly, you need to know more about nerve cells.


Q: What is the complex network of nervous tissue that carries electrical messages throughout the body?


A:
nervous system