The Brain – the basics

If you have suffered a traumatic brain injury you may have injured specific parts of your brain. To give you an overall understanding of the brain it’s important to look at all of the layers of the brain, their individual functions and how they work together. This will allow you to understand the impact of your brain injury, and work out any questions you may have for your healthcare provider.

The Cerebrum

The Cerebrum makes up the majority of the brain, accounting for around 85% of the brain mass. The Cerebrum is made up of two halves, the right and left hemispheres – which are then divided again into four lobes.

These lobes are:

The Temporal Lobe – the temporal lobe is partially responsible for processing our sensory information including hearing, language and memories. The temporal lobe also contains the hippocampus which is associated with thinking and feeling.

The Frontal Lobe – the frontal lobe is responsible for reasoning, problem-solving and regulating emotions.

The Parietal Lobe – the parietal lobe is responsible for some of our sensory information including touch, temperature and pressure.

The Occipital Lobe – the occipital lobe is the major visual processing area in the brain receiving information from both eyes which it then interprets into things including distance, identity and location.

Illustration of parts of the human brain

The Cerebellum

The Cerebellum is the second largest part of the brain and is responsible for functions relating to posture, balance and coordination. This includes coordinating movement through a number of muscle groups, coordinating eye movement, and gross and fine motor skills.

The Diencephalon

The Diencephalon is the third largest section of the brain. Located at the core of the brain, the diencephalon is the size of a plum and has two major parts – the thalamus and the hypothalamus.

The thalamus receives sensory information from all over the body which it then sends to specific areas of the cortex.

The hypothalamus lies just below the thalamus and is roughly only 1% of the brain mass. The hypothalamus has a number of functions, however, its main function is to ensure the body is stable (i.e. maintaining homestasis). The hypothalamus also responds to stress and controls the secretion of melatonin, cortisol and body temperature over a 24 hour period.

The Brain Stem

The Brain Stem is located at the base of the diencephalon and is made up of the midbrain, pons and medulla. Not only does the brain stem control basic body functions such as breathing, swallowing, heart rate and blood pressure, but it’s also responsible for the flow of messages between the brain and the rest of the body.

The Blood-Brain Barrier

The blood-brain barrier is the protective barrier around the brain. This highly intelligent barrier stops all of the bad stuff (like toxins) from getting into the brain all while allowing the good stuff (such as oxygen) to enter.


References and Further Reading


Frequently Asked Questions


New South Wales Government State Insurance Regulatory Authority – Mild Brain Injury Discharge Advice for Adults:

click here



Victoria Government Safer Care Victoria Emergency Care Clinical Network – Mild TBI Fact Sheet: click here


South Australian Brain Injury Rehabilitation Service – Concussion and Mild TBI Discharge Advice for Adults: click here


Queensland Health Clinical Excellence Division – Concussion Emergency Department Fact Sheet: click here

Queensland Health Clinical Excellence Division – Minor Head Injury without Concussion Fact Sheet: click here

Queensland Health – Minor Head Injury ED Fact Sheet: click here

Sunshine Coast Hospital and Health Service – Mild Head Injury Advice: click here


Government of Western Australia North Metropolitan Health Service – Mild Head Injury Advice: click here


Sydney Children’s Hospital Network Mild Head Injury and Concussion: click here


Children’s Health Queensland Hospital and Health Service – Infant Mild Brain Injury Concussion: click here

Queensland Health – Minor Head Injury in Children ED Fact Sheet: click here

Sunshine Coast Hospital and Health Service – Head Injury Care After Discharge: click here

What is an Aura in Migraines?

An Aura is a visual disturbance which accompanies a migraine with symptoms of an aura including visual disturbances such as flashing lights, trouble focussing, blind spots or bright zigzag lines. An aura can affect one or both eyes and can last up to an hour.1



Women’s and Children’s Hospital and Adolescent Brain Injury Rehabilitation Service: Concussion Infographic:

click here

Women’s and Children’s Hospital and Adolescent Brain Injury Rehabilitation Service: Concussion and Mild Brain Injury:

click here


Tasmania Government Department of Communities – Concussion Information for Parents Fact Sheet: click here


Perth Children’s Hospital – Head Injury Fact Sheet: click here

What is myelin?

Myelin is an insulating layer that covers the long processes of nerve cells within the brain and nervous system. It’s made up of protein and a fatty substance that allows nerve cells to more efficiently communicate with each other.

How does a free radical work?

When the brain is injured the concentration of some chemicals in specific cells or regions of the brain changes. The altered balance of chemicals can cause free radicals to occur. When a free radical is formed, it works to pull an electron from a molecule, which in turn makes that molecule a free radical. This can cause an unstable domino effect which causes disruption and further damage to the cells and structures of the brain.

What is Persisting-Post Concussion Symptoms (PPCS)?

Persisting-Post Concussion Symptoms is when the symptoms of concussion continue to affect the patient for months or even years following their injury. It is thought that PPCS is more likely to occur in those who have suffered from multiple concussions and there are a range of other risk factors that may increase the likelihood of PPCS.1


Committee on Sports-Related Concussions in Youth; Board on Children, Youth, and Families; Institute of Medicine; National Research Council; Graham R, Rivara FP, Ford MA, et al., editors. Sports-Related Concussions in Youth: Improving the Science, Changing the Culture. Washington (DC): National Academies Press (US); 2014 Feb 4. 4, Treatment and Management of Prolonged Symptoms and Post-Concussion Syndrome. Available from:

What is Chronic Traumatic Encephalopathy?

Chronic Traumatic Encephalopathy is a neurodegenerative disease that is observed in people who have suffered one or usually multiple TBI, including mild TBI or concussion. Symptoms may not show for years after the injury and the disease can only be conclusively diagnosed post-mortem. In CTE a protein called hyper-phosphorylated tau forms in specific structures in certain regions of the brain. Symptoms include altered mood and behaviours, aggression, depression and control problems. These symptoms may develop into progressive dementia.