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Breathe
5-16-2018
“Just breathe” has become a modern day mantra. Deep cleansing breathes can help relax the body and clear the mind. New age gurus extol the virtues of different types of breathing: square breathing, nasal breathing, diaphragm breathing, even Pranayama breathing which refers to the Sanskrit word for breath work in yoga. For something that primarily operates unobtrusively in the background of our awareness, breathing has taken on a life of its own.
We learn in primary school that breathing is the body’s way of bringing in vital oxygen and expelling out poisonous carbon dioxide. This simplistic representation masks the intricate elegance and precise balance indicative of our respiratory system. Each one of the 37 trillion cells that make up our bodies depends on our breath to remain alive. The human body does not have the capacity to store oxygen forcing us to continuously inhale and exhale approximately 20,000 times every day. Although we can consciously exert some control over breathing, when we intentionally hold our breath for longer than a couple of minutes the automatic nervous system overrides willpower by causing us to lose consciousness so that the subconscious control centre of the brain can take over and force breathing to resume. Under extreme circumstances our bodies can survive a couple of weeks without food, a couple of days without water, but only around 10 minutes without air.
This is because all of our trillions of cells, except for red blood cells, are constantly engaged in cellular respiration, thus requiring oxygen to be delivered “just in time” and carbon dioxide to be removed before it builds up to toxic levels. Our cells use the oxygen to break down molecules of sugar in order to release energy. It’s similar to burning wood in a fire. When cells use oxygen to break down sugar, changes occur resulting in carbon dioxide being produced and energy released that can be stored chemically for later use. All fire, including infinitesimal cellular oxidation, requires oxygen to burn.
If oxygen is the star of the show and carbon dioxide its foil, then iron and nitrogen are indispensable supporting actors.
Red blood cells make up over 80% of our body’s entire cell count and each one is packed with hemoglobin. Each red blood cell contains about 300 million hemoglobin molecules with each molecule containing four iron atoms. These tiny iron atoms are irresistibly attracted to oxygen. It is the presence of iron that gives hemoglobin the superpower to bond with oxygen which increases the oxygen-carrying capacity of blood by 65 times compared to water. Our 20 trillion red blood cells are like suitcases filled with oxygen travelling along the convey belts of arteries, capillaries, and veins. After being carried by the blood to a body tissue low in oxygen, the hemoglobin hands over its oxygen to an enzyme named monooxygenase which also has an atom of iron. The empty red blood cell now picks up the carbon dioxide hanging around and heads back to the lungs where there is plenty more oxygen to bond with.
But oxygen is not the only thing we breathe into our lungs. Regular air is mostly nitrogen at 79% not oxygen at 20%, with 1% assorted other gases and pollutants. Nitrogen is inert, therefore, it seems to play no physiological role in our body. Our cells neither use nor produce nitrogen and yet it is essential for health. This is because nitrogen keeps our lungs from collapsing. Human lungs are spongy with over 600 million alveoli clustered together - looking like teeny tiny grapes. These alveoli are elastic - inflating and deflating as we breathe in and out. Since the hemoglobin is seeking oxygen or carbon dioxide it pays little attention to nitrogen. It’s like a taxi driver who happily stops for passengers but does not try to pick up every pedestrian on the sidewalk. While some nitrogen enters the blood cell to go along for the ride most stays in the alveoli to hold the door open for oxygen and carbon dioxide to rush in and out of the lungs. Insufficient nitrogen can lead to collapsed lungs and other respiratory ailments.
When we breathe we can feel air entire through our mouth and nostrils. We we can see our chest rise and fall. We can speed up or slow down our breathing. But we don’t see, feel, or actively control the actual process of cellular respiration. We are a composite of trillions of cells, each one doing its part to keep us alive and healthy, and each dependent upon our breath. Pause to appreciate the marvel of your respiratory system. Just breathe.
Zainab Dhanani can be reached at z_dhanani@yahoo.ca
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