Together, they contain billions of nerve cells, called neurons. They are wired together in a huge network.
Neurons send information to each other through a fibre called an axon.
Bundles of axons are called nerves. Nerves are found throughout our body and gather information through our senses. This information is then sent to our CNS, where the brain processes it and tells our body what to do. For example, when it's really hot outside, your CNS tells the sweat glands to secrete water to help keep your body cool. The CNS also makes it possible for us to dream, remember, and think.