How the Brain works


Knowing how the brain functions will assist you in learning to understand and 'put together the pieces' in your own condition; why you behave the way you do, the symptoms you are experiencing and in Brain Health, Brain Nutrition and Brain Lifestyle what you can do about it. 

The brain or cerebrum serves as the command centre for the nervous system, it is the most complex part of the human body. Weighing in around 3 lbs it is one of the most heaviest organs of the body, it is such a demanding organ with requiring a lot of oxygen and uses up to 30% of the body's glucose requirements.
The brain is divided into two parts, the left cerebral hemisphere is associated with logic and controls the right side of the body, whilst the right cerebral hemisphere is about creativity and controls the left side of the body.

Apart from the cerebrum, there are two other important parts of the brain, the cerebellum and brain stem.

Cerebellum - located back of head by the neck
It is responsible for co-ordination of muscle movement, interprets information on balance from inner ear and filters information before sending to the brain.

Reduced functioning may result in:

  • Small muscle shake after movement
  • Inability to walk straight line
  • Inability to walk down stairs with no support
  • Dizziness
  • Car sickness, nausea when looking at patterns

Brain stem - located at the base of the brain, and ascends down the spinal cord
It is responsible for life support, involuntary actions such as breathing, heart beat

Now let's look at the structure of the brain itself, each half of the brain is further divided into four sections, each having its own unique responsibility.

1. Frontal lobe - located at the front of the head and stretches across our temples.
It is responsible for our personality and is involved in the action of impulses, activating muscles, emotional drive, planning and motivation. In addition to fine motor co-ordination such as sewing or handwriting. It is understood that children with attention deficit hyperactivity disorder (ADHD) may have delays in the development of this lobe.

Reduced functioning may result in:

  • In ability to commit to anything
  • Lack of project closure or follow through
  • Low motivation, resulting in laziness
  • Poor cognitive learning
  • Low mood
  • Poor handwriting
  • Reduced social behaviour and judgement

2. Temporal lobe - located either side of the brain.
It is responsible for the senses, hearing, talking, emotional responses and distinguishing smells. Within this area is the hippocampus which is involved in memory, learning, sense of direction,spatial orientation and sleep-wake cycle; and it is understood that damage to this area may result in poor memory leading to Alzheimers Disease. The hippocampus is involved in converting short term memory to long term memory, with long term memory being stored in the medial temporal lobe. Often early damage to the hippocampus may result in lack of short term memory recall whilst long term memory recall is functioning well.

Reduced functioning may result in:

  • Difficult in distinguishing tones
  • Poor memory
  • Insomnia
  • Low energy in afternoon

3. Parietal lobe - located behind the ears
This is divided into two sections, the first region involves sensation and perception, it integrates sensory information to form a single perception (cognition). The second region constructs a spatial co-ordinate system to represent the world around is. 
Responsibilities include sensations, touch and pressure, also signals from the eyes, muscles and skin.

Reduced functioning may result in:

  • Balance issues
  • Re-occurring injuries
  • Poor sensory perceptions

4. Occipital lobe - located at the back of the brain
It is responsible for processing visual information from the eyes, it is important to correctly understand what the eyes are seeing. This lobe has to be very fast in processing the rapid information the eyes are sending.

Reduced functioning may result in:

  • Difficulty processing visual information
  • Visual issues
  • Visual floaters in the eye

The Nervous System
The brain, cerebellum and brain stem belong to the central nervous system, whilst the nerves belong to the peripheral nervous system, they work together controlling our every movement and helping us to perform our daily activities. Nerves gather information from the environment, sends them along the nerves in the spinal cord to the brain, which then interprets the message and sends back a response.
The peripheral nervous system can be divided into the Autonomic Nervous System (ANS) which regulates involuntary, subconscious activities such smooth muscle tone, the heart rate and digestion and the Somatic Nervous System which controls voluntary, skeletal, muscle movement, conscious movement.

The ANS can then be divided into two systems, each working together to help create homeostasis in the body:

  • Sympathetic Nervous System (SNS) response prepares us for “fight or flight”, which is most commonly known for its increased heart rate, dilated bronchial muscles, increased blood pressure, and digestive slowdown. 
  • Parasympathetic Nervous System (PNS) response is described as “rest and digest”, which  promotes energy conservation such as a slower heart rate, decreased blood pressure, and bronchial muscle and urinary bladder constriction.

Nerve cells called neurons transmit messages from one neuron to another. This is a chemical reaction in which neurotransmitters are released and interact with the other cells. The action can either be an inhibitory or excretory action.

Then we have the Enteric Nervous System (ENS) located in the gut, which receives information from both the Autonomic Nervous System and Somatic Nervous Systems, regulating the gastrointestinal system. Often called the 'second brain' it communicates with the CNS through the PNS via the vagus nerve and through the SNS via the pre vertebral ganglia. The ENS can operate independently from the brain and spinal cord and is responsible for:

  • Control of peristalsis
  • Helps in churning of food
  • Secretion of enzymes
  • Modulates immune and endocrine functions
  • Use of neurotransmitters, with 90% of serotonin and about half of dopamine made in the gut

The gut brain axis consists of communication between the CNS and ENS, linking cognitive and emotional functions of the brain with intestinal functions. The microbiota (bacteria) in the gut has been shown to have an influence on this function.

Hence the GUT-BRAIN connection and with neurological disorders there is a need to look at the gastrointestinal function