Your brain is the real heart of what it means to be human. It has as many nerve cells (neurons) as the Amazon rainforest has trees: about 100 billion. Those cells share as many connections as the Amazon rainforest has leaves: about a billion in a piece of brain the size of a matchhead.

This vast network is responsible for what we think, how we feel and behave, how our bodies function and how we move. Here, we provide a guided tour of the key parts of your brain and what they do. Many activities are shared across different parts of the brain so, in most cases, it is important not to think of each part of the brain working alone. Much of what your brain does, such as forming memories, is shared across several parts of the brain as a whole.

Your brain: an introduction

Your amazing brain controls everything you do: your personality, thinking, speaking, right through to breathing and digestion. Find out more about the different parts on the the links below or use the link above for an introduction to the brain and the nervous system.

Your thinking cerebrum

Learn more about the decision-making centre of your brain.

The lobes of your brain

Learn more about the function of each of the lobes of your cerebrum.

Your balancing cerebellum

Learn more about the area responsible for movement and balance.

Your small but mighty brainstem

Learn more about this link between your brain and spinal cord.

Your emotional limbic system

Learn more about the reactive part of your brain, where your personality lives.

Your regulating pituitary gland

Learn more about this hormone-producing gland.

Your protective meninges

Learn more about the protective structure around your brain.

Your cushion of cerebral spinal fluid (CSF)

Learn more about the fluid that pads out and cushions your brain.

Glossary of words and terms

Here's a glossary of words and terms you may hear in connection with the brain.