Thursday, 23 September 2021

Something in the air

THE Guinness world record for the longest time breath has been held voluntarily is 24 minutes and three seconds. That is quite incredible (notwithstanding the rather sinister inclusion of the word “voluntarily”).

In reality, most people can hold their breath for only a minute or two. Clearly breathing, or rather the overarching process of respiration, is a compelling activity for the body and one that is not easily resisted.

There is a subtle difference between breathing and respiration. Breathing describes the inhalation of oxygen and the expulsion of carbon dioxide to and from the body respectively, whereas respiration also includes the transfer of these gases to and from the bloodstream along with the microscopic processes involved in producing energy from the conversion of oxygen to carbon dioxide.

Without the lungs, this would simply not be possible. With each breath, we inhale oxygen-rich air and this is taken to the very extremes of the lungs, through the trachea into the bronchi, the bronchioles and eventually to minuscule sacs called alveoli.

The alveoli are covered in tiny capillaries (the smallest type of blood vessel) with walls so thin that the oxygen can squeeze through into the bloodstream. From there it is taken in the blood to the heart where it can be pumped all around the body.

Every cell in the body needs oxygen to function, hence the reason our blood is so important.

Once in these cells, oxygen drives energy-making processes and, in turn, is converted to carbon dioxide. This is harmful in too great a volume so it is taken back into the blood where it is carried back to the small capillaries in the alveoli and deposited back in the lungs where it can be breathed out again.

Taking in oxygen and expelling carbon dioxide all happens in one breath, which is pretty impressive.

Such a complicated organ takes time to develop fully and the process starts even before birth.

Very early on, lung cells begin to develop from the tube that will eventually develop into the upper gastrointestinal tract.

As the weeks go by, these cells slowly create a separate tube that divides into two and then gradually branches out like a tree. This is how the ever narrower airways are created.

Towards the end of a pregnancy, the ends of these tiny airways develop into the alveoli, which grow their own blood supply.

In the womb, a baby has no cause to breathe air, so gains all of its energy from its mother’s blood supply. But in the first moments of life out of the womb this supply is abruptly cut, so a quick diversion of blood is made into the lungs and, as they fill with air, the baby begins to breathe.

In early life, the airways continue to develop and this often means infants are more prone to breathing issues if they develop coughs and colds.

By the time the lungs are fully developed, there will be between 300 and 500 million alveoli working away day in day out. The fact that they are rounded gives them more surface area to work with — if you were to lay out all the air-exchanging surface within a single pair of lungs, it would cover an area roughly equivalent to a tennis court.

Thankfully, the process of actually breathing is involuntary (we don’t have to think about it), which is useful for those with a busy schedule. The process is instigated and regulated by various parts of the brain (the medulla and the pons) but we retain the option to dip in if we wish to do a bit of conscious breathing if we feel like it.

The main element of control is the diaphragm. This is a dome of muscle that separates the abdomen from the thorax and, as it contracts, it flattens out, thereby lowering the pressure in the thorax, allowing air to enter the lungs (inspiration). As it relaxes, it moves upwards again, pushing air back out. An inherent elasticity in the lung tissue also helps in this expiration.

With such an important function, and owing to its close contact with the outside world, the lungs are susceptible to a plethora of different ailments.

Indeed, respiratory problems account for the greatest number of GP consultations and emergency admissions to hospital. Asthma on its own is the subject of between two and three per cent of GP consultations.

Chronic obstructive pulmonary disease (COPD), which is a term that encompasses a number of conditions, such as emphysema and chronic bronchitis, is another big issue and prompts a lot of medical input — about 1.2 million people are thought to have been diagnosed with this condition in the UK at present.

The difference between asthma and COPD is sometimes a subtle one. Asthma tends to be diagnosed earlier in life and is classed as a fully reversible condition that causes inflammation of the airways, often triggered by environmental factors (i.e. high pollen counts and poor air quality).

COPD, on the other hand, is not reversible and tends to be the result of cumulative damage to airways and so occurs in older age groups. Both result in obstruction of airflow and therefore difficulty in breathing.

When it comes to cancer, the lungs are no less vulnerable than any other part of the body. In fact, lung cancer is the most common cause of cancer deaths in men and women in the UK. It accounts for around 13 per cent of all cancers and in 2015 there were 46,388 new cases diagnosed. It’s a big issue.

Smoking, of course, is a massive factor, it being the biggest single cause of cancer worldwide.

In relation to the lungs, smoking is the biggest issue full stop, whether it be cancer, COPD or otherwise. One only has to look at the many pictures in circulation of lungs that belong to a smoker compared with those of a non-smoker to realise the phenomenal harm it does. That is why we bang on about it all the time.

So, in general, if we are thinking about keeping our lungs healthy, that is number one on the list every time. Stop it!

There are other things that may help:

Good hygiene and hand washing are important to reduce the chances of infection.

Aerobic exercise improves lung capacity over time and simple breathing exercises can also improve mood and aid relaxation.

Flu vaccinations annually, particularly if you are in at risk groups (pregnant women, asthmatics, diabetics, those over 65 years of age or with cardiovascular problems and carers).

A one-off pneumococcal vaccination for those over 65.

Hopefully that provides some inspiration for keeping your lungs as healthy as possible.

For more information on how to stop smoking, visit www.smokefreelifeoxfordshire.co.uk

Next time: The eyes.

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