What is the brain?
Our brains act as a control centre for all our bodily functions including breathing, heart rate and blood pressure. But the brain is also the organ that makes us who we are. Our brain gives us consciousness, personality and the ability to think, learn and remember. Having an understanding of what a healthy brain is and what it does can help when learning about brain injury.
The brain can be divided up into different areas that have different roles.More complicated tasks are performed by different parts of the brain working together.
How does the brain work?
The brain is about the size of a small head of cauliflower and weighs around 1.5 kg. The brain contains up to 100 billion nerve endings and is held together by layers of membrane and protected by the hard bone of the skull. Between the layers of membrane are blood vessels that supply blood to and from the brain.
A complex network of nerve cells (also called neurons) transmits information through electrochemical signals and impulses. These impulses travel around the brain and body through the central nervous system.
Different areas of the brain
The cerebrum is the largest part of the brain and is divided into two halves or ‘hemispheres’. Scientists believe that the left hemisphere is important in language, verbal memory, reading, writing and arithmetic, while the right hemisphere interprets vision, touch, non-verbal memory, music and emotions. Damage to the right side of the brain can affect the left side of the body, and vice versa.
Each hemisphere can be divided into four lobes – frontal, temporal, parietal and occipital.
- Frontal lobes. These are located behind the forehead. The frontal lobes control activities like thinking, planning and problem solving, and determine emotions and personality.
- Parietal lobes. These are located towards the back of the brain and affect perception, mathematical and spelling abilities.
- Temporal lobes. These are located behind the ears and affect memory, understanding, language and emotion.
- Occipital lobes. These are located at the back of the brain, and affect vision and understanding of written words.
Located at the back of the brain, the cerebellum controls balance, coordination and fine motor coordination.
The brainstem connects the brain to the spinal cord, allowing it to send and receive messages from the rest of the body via the nervous system. The brainstem also controls all the basic functions that we need to stay alive, including breathing, heartbeat, blood pressure, digestion, urination and sleep.
Other parts of the brain
Other smaller parts of the brain include the hypothalamus, pituitary gland and limbic system.
Located at the very centre of the brain, the hypothalamus controls body temperature, appetite, sexual arousal and emotions. The hypothalamus also sends chemical signals in the form of hormones to the pituitary gland, which then sends signals to other parts of the body.
The limbic system includes the hippocampus and controls emotional behaviour and long term memories.