THE BRAIN

Of the 30,000 million nerve cells in the body, some 14,000 million makeup your brain. The brain has three jobs to do. First, it receives information from sensory nerves about your body, eg stomach pains, or about the world outside. Second, the brain sends out instructions to all parts of the body – eg via motor nerves to the muscles in your hand. The third task of the brain  is to store and process the information it receives, so that, for example, you can understand and remember the words you see here.

Different areas of the brain are responsible for different activities. The largest part is called the cerebal cortex. This deals with receiving sensations and with conscious thought or control of the body. The cerebellum and other parts are responsible for unconscious control of the body.

·        The lobes on the sides, top and front of the brain are divided into the two cerebral hemispheres.

·        The left of the brain controls the right side of the body, and vice versa. This is because the nerves from the spinal cord cross over in the lower section of the brain.

·        At the base of the brain is a small part called the hypothalamus. This controls ‘automatic’ activities such as breathing, and maintains body temperature at about 37 degree centigrade.

·        At birth, your head was relatively large, weighing about 350g- almost one-tenth of the weight of the body. I n an adult the brain weighs on  average about 1400g – about one – fiftieth of the weight of the body.