Our brain is possibly the most complex organism in the known Universe and is capable of almost unlimited potential in our lives. Relatively small in size (representing around 2% of our total body mass at a little over a kilogram (2-3lb) in weight) it contains some 86 billion neuron cells (+/- 10%) and a similar number of non-neuronal cells. Each neuron may be connected to up to 10,000 other neurons, passing electro-chemical signals to each other via connections called synapses. Our brain has as many as 1,000 trillion synaptic connections, equivalent by some estimates to a computer with a 1 trillion bit per second processor!¹
It literally controls and processes everything we do, everything we are. From before we leave the womb to shortly after we die (or could be pronounced ‘brain dead’ which is a bit of a ‘fuzzy’ term capable of differing interpretation! )
Fig 1. Two diagrams representing a typical human brain – the colours were added to more clearly display areas of our brains that serve mainly one type of function.
Fig 2. A closer to real image of a human brain which is largely pink when living, with red blood flowing through it. Human brains we are most likely to see are generally greyish in colour having no blood and most likely have been stored in a preservative, hence ‘grey’ matter referred to when someone is using their brain.
Although the Cerebrum, which is the main part of the brain we normally see with all the folds and valleys, is the largest part of our brain it only contains about 20% of the neuron cells, while the large majority – 80% – are contained in the smaller cerebellum region tucked in the back and underneath the cerebrum/cortex. (You can just see it sticking out underneath in Fig 2.)
The Cerebrum, or Cerebral Cortex, is a major part of the brain, controlling emotions, hearing, vision, personality and much more. It controls all voluntary motions/actions.
It functions as the center of sensory perception, memory, thoughts and judgement. The sensory areas of the cerebral cortex receive and process visual, auditory, somatosensory, gustatory, and olfactory information. Together with association cortical areas, these brain regions synthesize sensory information into our perceptions of ourself and of the world. Speech and language, learning and memory are also controlled as functions of the cerebrum.
The cerebrum is divided into to symmetrical halves known as the left and Right Hemispheres, which are connected via a densely packed bridge of neurons known as the Corpus Calossum. The cerebral cortex is generally classified into four regions called lobes: the frontal, parietal, occipital and temporal lobes.
The Cerebellum plays the major role of fine tuning and synchronising our motor movement and balance and is also involved in some cognitive functions, such as attention and language, as well as in regulating fear and pleasure responses. The cerebellum and its auxiliary structures can be separated into several thousand independently functioning modules called “microzones” or “microcompartments”.