THE NERVOUS SYSTEM

We have a very good nervous system, which tells us what goes on in every part of our body. The brain controls the system and is like a telephone exchange, with the nerves- the wires- receiving and sending messages all over the body. The two main parts of the nervous system are the central nervous system and the peripheral nervous system consists of the brain and the spinal cord. The peripheral nervous system is made up of the nerves which send messages to the brain from the senses and which take messages from the brain to the glands and muscles. Every muscle and sense organ has to be connected.

·        Nerves are made up of cells called neurons. These have thread-like arms called dendrites which pass impulses down the cell’s one long arm or axon, to other cells. Impulses consist of very weak electrical currents.

·        Because the verves endings are continually receiving information from their surroundings, they are called receptors.

·        Messages travel along  nerves as electrical impulses at speeds of up to 400km/hr.

·        In reflex actions, messages travel to and from the spinal cord without the brain being involved.