11 April 2006


Your lungs are hard-working organs, inhaling and exhaling from 15 to 25 times per minute (more when you’re exercising), and you probably often take them for granted.

Your lungs make use of that most ethereal of materials – thin air. These are hard-working organs, inhaling and exhaling from 15 to 25 times per minute (more when you’re exercising or excited), and you probably – if you’re like most of us – often take them for granted.

What are lungs exactly?
The lungs are two spongy, elastic, balloon-type organs that expand and contract as you breathe in and out. A healthy pair are a delicate pink, but if abused by smoking, they start to look grey... remember those gross pictures you were shown at school during anti-smoking talks?

Where are the lungs exactly?
Your lungs are situated within your rib cage, which forms a sort of enclosure for them together with the diaphragm, a dome-shaped muscle located at their base. The ribs are connected to each other by muscles called the intercostals. Ribs, lungs, muscles and connective tissue are all connected, and move together as a unit when you breathe.

What your lungs do for you
Basically, your lungs’ life work is to extract precious oxygen – needed by every living cell – from the air, and get rid of carbon dioxide, one of the body’s waste products.

For some reason, maybe because it’s not quite as vital (at least not for most of us), we forget that the lungs also make it possible to do something else apart from breathe: they let us talk. Your voice is a working combo of the lungs and vocal chords; without exhaled air, the vocal chords can’t vibrate, and you wouldn’t be able to talk – or whisper, shout, laugh, sing in the shower or be a real man (cry).

Down the tubes
The lungs are connected to the atmosphere outside by a series of tubes. Air enters your nose or mouth as you inhale, then continues down the back of your throat and down the windpipe. The windpipe branches into two tubes, the bronchi, each of which leads to a lung. In the lungs, the bronchi divide into smaller and ever smaller tubes, which eventually end in tiny air sacs called alveoli. Each one of these is enclosed in a net of blood vessels. Oxygen from the inhaled air moves from the alveoli into the blood, and carbon dioxide moves from the blood into the alveoli, to be expelled when you breathe out. How the breathing mechanism works
Inhale: the intercostal muscles contract, moving the ribs further apart, increasing the space within the chest cavity. The diaphragm also flattens, increasing the space even more. The larger space means lower air pressure inside your chest cavity than in the air outside; air molecules are pulled in through your nose from the higher air pressure outside to the lower pressure inside, inflating your lungs.

Exhale: the muscles relax, making the chest cavity smaller. As the volume decreases, so the air pressure increases. Air in the lungs moves from the higher pressure to the lower pressure of the air outside the body.

And repeat, about once every five seconds, about 20 000 times a day, for the rest of your life.

What you can do for your lungs
Well, it’s not a good idea to fill your lungs with hundreds of toxins and carcinogens on a daily basis. To put it another way: don’t smoke. And don’t let people smoke around you, either. There’s now no question that second-hand smoke also ups your risk for heart disease and lung cancer.

Tobacco smoke is the numero uno environmental pollutant to avoid, but do your best to also stay away from other bad air zones: busy roads, especially at rush hour, and industrial areas. If your work or hobbies bring you into contact with potentially damaging airborne substances (dust, solvents etc.), make sure you know and follow the safety guidelines for working under these conditions.

Love your lungs with exercise, specifically of the aerobic variety i.e. anything that gets you puffing. With vigorous exercise, your cells demand extra oxygen, which requires more air and deeper breaths, which makes your lungs stronger in the long run.

Did you know?

  • You take in about half a litre of air with each breath – more when you’re exercising.
  • Your lungs aren’t the same size: the left lung is a bit smaller than the right lung, to leave some space on the left hand side for your heart.
  • If you flattened out all the alveoli in your lungs, they would cover a tennis court.


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