Your Marvellous Brain

The human brain is possibly the most complex and fascinating of all the organs in the human body. Weighing in at only about 1.5kg (3 pounds), it is the most impressive biological computer. It has been suggested that the storage capacity of the human brain is 3 million years, which means that you and I truly have a remarkable capacity to learn and store information (Dr. Caroline Leaf, Who Switched off my Brain?, 2007). By applying the brain, dendrite connections between brain cells (neurons) grow thick and lush much like a well watered forest. Let's take a step back. What are dendrites and what has a forest got to do with the brain?

Our brains are part of the central nervous system, which also include the spinal cord. The other part of the nervous system is called the peripheral nervous system which controls the voluntary muscles (somatic nervous system) and the involuntary muscles (automatic nervous system). The automatic nervous system is involved in the fight-and-flight response and is activated when we need to get out of a sticky situation very quickly. This is known as the sympathetic response which causes the adrenal glands also pump adrenalins, epinephrine and norepinephrine into the bloodstream.

The endocrine system works together with the nervous system as lightning fast messages are sent between the amygdala (area associated with deep emotions and fear), hippocampus (important part of memory storage process and emotions) and the hypothalamus (secretes chemicals to activate the adrenal glands). As a result, the heart starts to beat faster, breathing rate increases, digestion is halted to conserve energy, blood flow to the brain and active muscles increase and pupils start to dilate to increase visual sensitivity. This reaction assists us to respond with physical strength and with mental sharpness under threatening circumstances.

When a person makes a conscious decision using the frontal lobes of the brain that the threat no longer persists the fight-and-flight response can be shut down. The parasympathetic response returns the body functions to a normal, calm and healthy pace. It is possible that people who suffer from anxiety activate the fight-and-flight response too frequently.

Returning to the normal relaxed state after a traumatic incident is crucial since an extended period in fight-and-flight is related to stress, burnout and Post Traumatic Stress Disorder (PTSD). The high levels of adrenalin keeps a person from relaxing and sleeping. Sleep is crucial for mental and physical health. The lack of sleep can affect mental alertness, concentration, immunity and eventually even lead to manic episodes if sustained over extended periods.

Functioning at a high stress level also places enormous pressure on other systems in the body such as the cardiovascular system, immune system and digestive system. It is therefore not unusual to associate high stress and anxiety with heart problems, health issues and problems with the bowel such as irritable bowel syndrome.

We have just considered the remarkable response of the brain to assist us in an emergency situation. It is the seat of our emotions, memories, physical responses to stimuli, and our information storehouse. We are all born with about 200 billion brain cells (neurons), each with the potential to grow 70 000 dendrite branches. When we apply our brain cells, new branches are formed and connections between brain cells are strengthened. When this happens, we learn and are able to make even more connections than before. If we do not use our brain cells, they dystrophise and disappear, in the same way that an unused muscle would wither away.

Most of use lose about half the amount of brain neurons that we were originally born with by the age of two. Newborns therefore have a very necessary surplus of neurons to assist them in the new journey of life. They have tremendous capacity to learn, after all, from the moment of birth they are in a buzzing new learning environment of sights and sounds, touch and taste, and they develop a growing awareness of internal and external sources of pleasure and discomfort. Young children also have a greater capacity than adults to learn multiple new languages.

Adults who already can speak multiple languages generally find it easier to learn even more languages. The reason for this is because the neuronal dendrites (branches) in the language areas of the brain are already densely developed. New language information is more readily stored and retained because of associations with the languages that are already mastered. As a point of interest, rhythm and balance are important components in language acquisition. I suspect that is why it is so much easier to learn a new song than to memorise a paragraph!

Neurons generate electrical signals that travel along their axons. When a pulse of electricity reaches a junction called a synapse, it causes a neurotransmitter chemical to be released, which binds to receptors on other cells and thereby alters their electrical activity. (Source of illustration and heading:

The communication between nerves in the brain and body are both a chemical and electrical event. Below is an illustration of the neurons with the dendrites and axons.

The capacity of our brains can also be limited or impaired. It is evident from the information already shared that we often simply do not always utilise the brain so that it can develop optimally. We also may focus on specific areas of interest and neglect others. Trauma may affect our brains so that we remain in a flight-and-fight mode, and react and respond to our environment and others in a continuous and ineffective self-preservation style. Another reason is simple neglect. In a modern lifestyle it is not uncommon to subject our brains and bodies to poor sleeping patterns. Modern processed foods are designed to cater for the masses and as such our individual health suffers. When our food lacks nutrients, our bodies are deprived from brain foods that support effective brain function and healthy mood states. Besides depriving the brain, another manner in which it can be abused is by flooding it with harmful chemicals and toxins such as excessive alcohol and other drugs. Since the brain is eager to learn, continuous exposure to such unhealthy inputs create new habits. Addictive neural pathways are developed over time that support and strengthen behaviours and habits that keep the brain stuck in this destructive cycle. Brain function such as memory, inhibition, rational reasoning, concentration and language skills are often compromised as a result.

The ability of the brain to change and learn is called brain plasticity. The previous paragraph describes how unhealthy inputs can create unhealthy outputs as far as the brain is concerned. But the opposite also hold true. When we nurture the brain with good nutrition and we exercise it by exploring a variety of interests and solving increasingly complex problems, it will develop and learn. If we work through traumas and forgive hurtful memories, it will heal. When we expose ourselves to beauty, fun and laughter, it will be filled with joy. If we learn to be grateful and kind, it will transform our relationships... and perhaps even the little bit of the world around us.

It is your lifetime servant. Irreplaceable and precious. It is . . . your marvellous brain!

Written by Dr Ingrid Artus