The spinal cord is a thick bundle of nerves which runs down the centre of the spine. This is like a freeway.

Along the spinal cord smaller bunches of nerves branch out. These are like highways.

From these bundles, smaller bundles of nerves branch out again. These are like main roads.

Finally, individual nerves branch out to every part of the body. These are like normal roads.

This network of nerves allows the brain to communicate with every part of the body.

Nerves transmit information as electrical impulses from one area of the body to another. Some nerves carry information to the brain. This allows us to see, hear, smell, taste and touch. Other nerves carry information from the brain to the muscles to control our body's movement.

Many drugs, such as alcohol and cigarettes, affect the way that our nerves work. This can result in us not being able to control our body, as well as we should.