Kids Health Info

Brain injury - How the brain works

  • The brain is made up of different parts including the cerebrum, the cerebellum and the brain stem. The effect of brain injury will depend on which part of the brain has been damaged.

    Parts of the brain

    Nerve cells in the brain send and receive electrical impulses to and from the body. If you take a close look at the human brain, you'll find it has three main parts.

    The largest is the cerebrum on top. The surface of the cerebrum is called the cerebral cortex. Although less than 0.5cm thick, the cerebral cortex is critical to your child's ability to move, to understand what they see and hear, and to think - a complex process of making decisions, learning, remembering, and planning.

    The cerebrum is divided into two halves called hemispheres. The corpus callosum is an 'electric highway' of nerve fibres which connects the two hemispheres and allows information to pass between the two hemispheres. The hemispheres are divided into smaller parts; the frontal, temporal, parietal and occipital lobes.

    At the back of your brain and beneath the cerebral cortex is the cerebellum. This coordinates skilled movement, giving your child the ability to walk without stumbling, and use their hands smoothly and precisely.

    Located at the base of the brain is the brain stem, a stalk-like structure that connects it to the spinal cord. The brain stem takes care of basic, involuntary functions, such as breathing, blinking and bowel regulation.

    How the brain works RCH KHI

    Figure 1 The Brain Areas

    What are the effects of injury to the different areas of the brain?

    In focal brain injury, just one lobe in one hemisphere may be affected. In diffuse injury, all lobes of both hemispheres may be affected. There are connections between the different areas of the brain, and damage to one area may result in dysfunction associated with other parts of the brain.

    Frontal lobes

    The frontal system controls many complex functions, which are referred to as executive functions. These include planning, control of impulses, initiation, attention and emotion. The back of the frontal lobe also controls movement of the opposite side of the body. Damage to the frontal system (that is damage to the frontal lobes directly or connections to the frontal lobe) may cause changes in behaviour, attention, emotions and also weakness to the opposite side of the body.

    Parietal lobes

    The parietal lobes provide sensory information to the brain, including touch, pain and temperature. Damage may cause the child to lose sensation down the opposite side of the body. This may result in the child being less aware of parts of their body (sensory neglect).

    Temporal lobes

    The functions of the temporal lobes include hearing, memory and learning. Damage may cause difficulties with organising what to say, and finding and using the correct words. It may also result in difficulties with short-term memory.

    Occipital lobes

    The occipital lobes help us understand what we see. They interpret the colour, shape and distance of what we look at. Damage may result in a distortion of what is seen and difficulty recognising or interpreting familiar objects.

    Cerebellum

    Damage to this area may result in movement becoming jerky or uncoordinated known as cerebellar ataxia. The child's speech may also become slurred and difficult to understand. The cerebellum has rich connections to the cerebrum, therefore damage to the cerebellum can result in disruption of functions controlled by other parts of the brain.

    Key points to remember

    • The central nervous system is made up of the brain, the brain stem, the cerebellum and spinal cord.
    • There are different areas of the brain including the frontal, parietal, temporal and occipital lobes.
    • The effect of brain injury will depend on what part of the brain, and/or connections to an area within the brain are damaged.
    • Functions that are controlled by one part of the brain can be disrupted when connections to it are damaged due to brain injury.

    For more information




    Developed by the RCH Paediatric Rehabilitation Service,based on the How the brain works factsheet produced by the Brain Injury Service, The Children's Hospital at Westmead.First published Feb 2007. Updated November 2010.
Disclaimer
This is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easily understood. The Royal Children's Hospital accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in the handouts.