An introduction to your brain

Your amazing brain controls everything you do: your personality, thinking, speaking, right through to your digestion and breathing.

Your brain contains billions of nerve cells (neurons). They are microscopic cells that carry messages to and from all parts of your body, using electrical and chemical (electrochemical) signals.

Your brain is part of a huge network of neurons known as the nervous system. This split into the central nervous system (CNS) and the peripheral nervous system (PNS).

The CNS includes your brain and your spinal cord. The spinal cord is a bundle of nerves that run up and down your spine, communicating high-speed messages between your brain and your lower body.

The PNS is comprised of all the nerves that travel between the CNS and every organ in your body including your eyes, mouth, heart, gut, fingers and toes.

Your peripheral nerve endings pick up sensory stimuli (such as touch, temperature, pain, and visual and auditory stimuli) and send impulses up sensory nerves to your CNS. Here, the information is interpreted and you become consciously aware of it when it reaches your cerebral cortex.

Your brain then responds by sending action instructions back to your peripheral nerves through motor neurons. This causes the appropriate parts of your body to react or move.

Your brain is split into many parts: the main parts are the cerebrum, the cerebellum, and the brainstem. Other key parts are the limbic system, pituitary gland, meninges and the cerebral spinal fluid.