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The brain is one of the largest (it weights three pounds)[1], most vital organs in the human body; without the brain, life would not be possible.

The human brain is comprised of approximately 100 billion nerve cells that communicate with one another by means of trillions of connections called synapses.

The brain receives the information input (stimuli) by means of the sensory organs and utilises its processing capacity to mediate an appropriate response(s).

The brain is located within the skull (the cranium) for protection[2], and is surrounded by a group of membranes called the meninges consisting of the dura mater, the arachnoid and the pia mater.

In addition, the brain is surrounded by cerebrospinal fluid (CSF) which provides more protection, cushioning the brains cortex by filling the dead-space in between the arachnoid membrane and the pia mater.


Basic structure and function

The brain can be divided into four main components, the first being the cortex, the outermost layer of brain cells (neurons), which is involved in higher thought processes including speech, decision making and involuntary movement.

The basal ganglia are a cluster of structures found within the centre most region of the brain which facilitate the coordination of electrical impulses within different regions of the brain.

The cerebellum is found at the base of the brain and is associated with coordination in space and balance, with the brainstem being located between the spinal cord and the remainder of the brain controlling our most basic functions such as breathing, heart rate regulation and blood pressure.

The 'plastic brain'

Neuroplasticity is the ability of the human brain to change its structural organisation based on learning and experience, which shapes the brain map.

New connections will form between different neurones when we learn a new skill and some older connections are lost if we do not rehearse specific skills in our personal repertoire.

Due to traumatic events, there can be a functional shift in the brain map, which can lead to dramatic changes in the order and structural organisation of the brain.

Maguire et al. (2000) proved that there was an increase in the volume of grey matter in hippocampi of taxi drivers over the course of time, during which spatial navigation capabilities of these taxi drivers increased[3].

Left and Right Brain:

The corpus callosum are bundles of fibres that connect the left brain and the right brain together and this delivers messages from one side to the other. Each side controls the opposite side of your body. For example, your left arm is controlled by your right side of your brain. In addition, not all the functions are shared between the two sides i.e the left hemisphere controls speech, and writing. The right hemisphere controls creativity, artistic, and musical skills[4].


  3. Maguire EA. Proc Natl Acad Sci U S A. 2000 Apr 11;97(8):4398-403.
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