Smorgasbord Health Column- The Lungs – The race is on – 6 minutes to get oxygen to the brain

The Lungs.

We only have a very short period of time between stopping breathing and our major organs such as the heart and brain becoming oxygen starved and dying.  In fact about six minutes depending on age and fitness and the circumstances.

Despite being the bellows that keep these two major organs alive, the lungs rarely get press – unless it is part of a stop smoking campaign – yet if you were to examine the death certificates of people over 80 years old for the last 100 years or so you will probably find that pneumonia is the number one killer.

There is a reason we have a rib cage and that is to protect the major organs that keep us alive. When you look at all the posed pictures in the media of celebrities and their selfies, one would assume that the chest area was purely cosmetic. In fact it houses the engine that keeps us running.

Without oxygen both the heart and the brain would cease to function in just a matter of minutes – so ensuring the health of our lungs is vital. This is partly achieved by leading a healthy lifestyle, including taking exercise and not smoking, but there are also hidden dangers to the health of our lungs in our environment and in the food that we eat.

There are many diseases associated with our lungs, including cancer, asthma, acute and chronic bronchitis, emphysema and silicosis and of course pneumonia. Some of these I will look at in later blogs for a little light reading! The early symptoms of these diseases are easy to miss and confused with cold and flu symptoms so understanding the structure of these organs and how they operate could make a difference to how fast you receive treatment for potentially serious diseases.

Eating healthily will certainly decrease your risk of contracting some of these diseases but it is also important to monitor your immediate environment carefully to avoid possible contaminants and triggers for poor lung function. Later in the posts, I will cover the effect that cigarette smoke has on the lungs – and being a non-smoker yourself is little protection if the people around you continue to blow smoke into your airways. (There is nothing worse than a reformed smoker!)

All our cells need oxygen. Our nose is not just a pretty feature on our face and serves a vital role as the filtration system for the air that we breathe. As we inhale air into the nasal passages it is cleaned, warmed and humidified before entering the pharynx.

The pharynx is the area at the back of the mouth and slightly down into the throat. There are a number of parts to the pharynx and the upper part is called the nasopharynx and forms the back of the nose. The lower part of the pharynx is at the back of the mouth and forms part of the airway from the mouth and lungs and is called the oropharynx and the muscles here help shape the sounds of speech as they come from the larynx.


The larynx or voice box sits between the pharynx and the trachea. It is made up of cartilage and connective tissue. A flap at the top of the larynx is called the epiglottis and this ensures that air can enter the trachea in the open position but it can shut to prevent food from also getting into the airways. Most of us have inhaled something, like breadcrumbs in the past, which has led to a coughing fit and this is when the epiglottis has failed to shut quickly enough. It is vital that foreign bodies do not enter any further into the airways and the coughing reflex is actually a very strong survival trait. If particles of food reach the delicate lining of the lungs it can cause an infection to build up leading to pneumonia. It is also another good reason not to talk with your mouth full!

Across the larynx are the vocal cords which are responsible for our speech and these can become inflamed and sore when we have been shouting or singing too loudly and have caused mild damage to the cords.

From the larynx the air will pass into the trachea which is more commonly known as the “windpipe” and this splits into two bronchi taking air into the right and left lobes of the lungs.

The lungs

Lungs & Diaphragm

The lungs are two air sacs of differing sizes that fill the thorax, which is the part of the body between the neck and the abdomen. The thorax is encased in the safety of the rib cage supported by intercostal muscles and protects both the lungs and the heart. At the bottom of the thorax is the diaphragm, a dome shaped muscle which separates the chest cavity from the abdomen.

The right lung is larger than the left as the heart takes up a lot of room on the left side of the chest cavity. Each lung is divided into lobes with three in the right lung, upper, middle and lower and two in the left lung, upper and lower.

The lungs are kept open by a thin, fluid lining around the lungs and the chest wall called the pleural membrane, which creates surface tension. This also allows the lungs and chest wall to move easily together as you breathe. When the chest expands to inhale air the lungs are pulled towards the chest wall by the tension, expanding their capacity. When we exhale air the muscles relax slowly allowing the lungs to deflate gently. If that surface tension is broken by air getting between the chest wall and the lung, the lung springs back too suddenly and it results in a pneumothorax or collapsed lung.

The Pleural membrane.

Inside the lungs there is a network of tubes of varying sizes. The bronchi are the muscular tubes that bring the air into each lung and here they separate again into two smaller size bronchi before branching out into much smaller bronchioles. These bronchioles end in elastic and thin walled air sacs called alveoli. As an essential part of our immune system, on the inside of each alveoli are white defensive blood cells called macrophages, which trap and destroy any inhaled bacteria and other toxins preventing disease.

As the lungs are vital to the supply of oxygen to the rest of the body there needs to be an exchange system once the air is in the lungs. The pulmonary arteries run parallel to the main bronchi as they enter the right and left lungs and they also branch out into smaller and smaller blood vessels running beside the bronchioles and when they reach the alveoli they form a network of capillaries around them. The oxygen from the air is then transferred to the capillaries and then onto the pulmonary vein, out of the lungs and into the left side of the heart. In a reverse process the carbon dioxide which has been collected by the blood from the body is transferred back into the alveoli up through the network of tubes and out of the body.

How do we breathe?

The pressure inside and outside of the body is different. Humans breathe in an average air pressure of 760 mm Hg (millimetres of mercury) or 14.7 lbs. per square inch. This is called one atmosphere of pressure and is measured at sea level. If you have watched mountaineering programmes you will be familiar with the breathing difficulties associated with higher altitudes and this is because the majority of us are adapted to breathing at sea level. Of course cultures that already live at altitude are acclimatised and have no problem with working with an alternative pressure.

Before taking a breath the pressure is almost equal inside and outside of the chest cavity. During an intake of breath the diaphragm contracts and increases the size of the chest cavity, dropping the pressure inside the lungs and in the space between the two layers of the membrane around the lungs, called the pleural space. Air rushes into the lungs to equalise the pressure. As the diaphragm relaxes and pressure rises in the chest cavity to equalise the pressure again the air is exhaled.

Posts that will be coming up in the series

Acute and Chronic diseases that can take your breath away!
Asthma – The symptoms, the attack and the reactions necessary to resolve.
Pneumonia – the most common cause of death of children worldwide!
 Lung Cancer. I know you are fed up being told to stop smoking but…….
 The Good News – How you can nutritionally support your bellows…..

© Sally Georgina Cronin – 1998 – 2020

I am a qualified nutritional therapist with twenty-two years experience working with clients in Ireland and the UK as well as being a health consultant on radio in Spain. Although I write a lot of fiction, I actually wrote my first two books on health, the first one, Size Matters, a weight loss programme 20 years ago, based on my own weight loss of 154lbs. My first clinic was in Ireland, the Cronin Diet Advisory Centre and my second book, Just Food for Health was written as my client’s workbook. Since then I have written a men’s health manual, and anti-aging programme, articles for magazines and posts here on Smorgasbord.

If you would like to browse my health books and fiction you can find them here: My books and reviews 2020

Your feedback is always welcome and if you do find that following any of the series that I have shared are beneficial then it would be great to hear about it.. you can email me on

16 thoughts on “Smorgasbord Health Column- The Lungs – The race is on – 6 minutes to get oxygen to the brain

  1. Sally, very complete, informative post on the lungs. Care of the lungs one aspect of staying healthy. Look forward to your other health related posts. This is important reading for all! Christine


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