THE brain is made up of two halves.Different areas of the brain have different functions.All nerve cells in the brain , about 100.billion of them are connected to one another and transmit information.This network of nerve cells is expanded through learning and training. Our brain controls our actions , regulates our sleep and allows us to feel sensations like pain and joy.If it is damaged ,due to stroke or some other reason ,one has to relearn a lot of things like speaking, walking,or eating. NERVE CELLS TRANSMIT SIGNALS .This process is quite complicated.Like other cells ,nerve cells also have a cell body with a nucleus .These are fine extended branches known as dendrites and a long tail called axon on the body of the nerve cells.Axon in the brain are smaller than 1mm, whereas in the spinal cord they can be as long as