The Brain

The brain, do you really know what's going on?

It's what we use every second of our lives, and is the most incredible organ that still keeps scientists busy trying to understand it.

But how much do you really know about it?

The adult brain weighs about 1.2 kilos, or about 2.5 kilos of a persons body weight. Which is not much considering it controls everything we do. The amazing thing about the brain is that although it is relatively small in weight compared to the rest of the body, it consumes up to 15% of the blood supply that the body receives. Of that 15% of blood the brain utilizes 25% of the oxygen in the body.

The are four major sections of the brain which include the cerebrum, the cerebellum, the diencephalon, and the brain stem which all contribute to various functions within the body.

The cerebrum (cerebral cortex)

The major portion of the brain is made up of the cerebrum, which occupies most of the inside of the skull. The cerebrum is responsible for our ability to smell, speak, move, taste, see and hear. You may have heard that a hard hit to the back of the head can cause blindness, which in fact is true, as the back of the brain affects vision. It is the cerebrum that enables us to think. The areas of 'thought' are located at the front of the brain. This is an incredible part of the brain, still baffling scientists as to how it works so harmoniously.

The cerebellum

One of the main tasks of the cerebellum is to maintain balance. This is achieved through three different processes, which include vision, impulses caused by the effects of gravity, and the inner ear. The information gained through these three things are brought to the cerebellum and processed into equilibrium. The cerebellum is also responsible for the execution of fine movement and muscle coordination.

The diencephalon

The diencephalon contains three vital structures, the thalamus, the hypothalamus, and the epithalamus.

The thalamus: plays a key role in memory, maintaining sensation, motor (movement) activities. It is sometimes referred to as the gateway to the cerebrum (cerebral cortex).

The hypothalamus: is a very primal part of the brain. It is very deep within the brain, so as to protect it from injury. It is the centre of autonomic control, regulating heart rate and force, blood pressure, respiratory depth and rate, digestive tract motility, and size of the pupil in the eye. It also controls body temperature, regulation of food and fluid intake, sleep cycles and hormonal functions. It is extremely important to maintain the normal function of the brain and body.

The epithalamus: plays a role in sleep regulation, along with some aspects of 'mood'.

The brain stem

The brain stem is situated almost directly in the centre of the skull. It is the connection to the spinal cord and the higher brain centres, so that all the information processed in the brain can be passed on to the rest of the body. The pons, medulla oblongata, and midbrain make up the brain stem. These structures help the brain maintain the body's autonomic processes (non-conscious actions) such as breathing, and control of various major nerves of the skull such as the facial nerve.

The facts on "lefty's" and "righty's"

For most people (around 90%), the left hand side of the brain is the dominant side and has the most control over language, math's, and logic. The right hand side of the brain is usually associated with visual-spatial skills, emotions, intuition, and the ability to appreciate music and art. This is the side of the brain that is responsible for the creative side, along with the insightful side. For example, it is this side of the brain that helps us to recognize faces. Most people who have left sided dominance are 'right handed'.

The other remaining 10% of people are either reversed in their hemisphere dominance or have equal functions of both sides. Typically right-sided dominance is associated with 'left handers' and who are more likely to be males. Left-handed people are more likely to be ambidextrous (can use both sides of their brain equally), therefore they are sometimes able to write with both hands (however this is not the written rule).

Whichever side is dominant, in normal cases the two sides work together in unison, so that the intellectual hemisphere does not have complete control, and works with the non-dominant hemisphere to make decisions. This actually prevents us from making rash decisions. For example, if you need a rest from work the non-dominant side will help you to negotiate a rest, and you may begin day dreaming, or take some kind of break. Then when you have rested, your ability to make decisions is more accurate. This is important for everyone when it comes to making clear decisions. This is normal, and it keeps a balance (and our sanity). If the two hemispheres do not work together (this is a problem the individual is usually born with) and the result can be problems such as dyslexia (a learning disability).

In most cases the brain works incredibly harmoniously, in a way that is slowly, but surely being uncovered by scientists.

- Louise Ganey (RN)