6 The Nervous System

THE NERVOUS SYSTEM

THINKING BIG Hello! I'm your brain. I'm a big part of your nervous system. The nervous system controls all activities in your body. The different parts of your body must work together precisely to carry out even the simplest action. Your nervous system coordinates all these different tasks!

It directs your movements... ...focuses your eyes... ...commands your muscles to contract... pum pum pum pum ...senses your surroundings, and feels your pain! Zip Without a nervous system, life as you know it would be impossible! catch

THE NERVOUS SYSTEM If you look really close... ...you can see that the human nervous system is made up of billions of special cells called neurons. Neurons work together to form tissues! Cordlike bundles of neuron fibers are called nerves. Nerves carry messages from your sense organs, such as your eyes, ears, nose, and touch sensors in your skin.

Some of these messages travel along a pathway of nerves until they reach your spinal cord. From there, the messages travel to the brain. The network of nerves in your body enables you to react to your surroundings in an instant!

PARTS OF THE NERVOUS SYSTEM 1 The nervous system is divided into two main parts: The central nervous system, or the cns... 2 ...and the peripheral nervous system, or the PNS. The PNS is made up of all the nerves that carry messages to and from the central nervous system to the rest of your body.