The brain controls complex behaviour. It is made of billions of interconnected neurones and has different regions that carry out different functions.
The four main areas in the brain are:
The cerebrum (the outer layer is called the cerebral cortex), which is split into two hemispheres and is highly folded. It controls intelligence, personality, conscious thought and high-level functions, such as language and verbal memory.
The cerebellum, which controls balance, co-ordination of movement and muscular activity.
The medulla, which controls unconscious activities such as heart rate and breathing rate.
The hypothalamus, which is the regulating centre for temperature and water balance within the body.