How your lungs work

Interesting lung facts

• Did you know that your left lung is smaller than your right lung? This is to make room for your heart.¹
• You get rid of 70% of waste from your body just by breathing it out through your lungs.²
• Can you live with one lung? Yes, you can! While it might limit how much physical activity you can do, it doesn’t stop you from living a relatively normal life. Many people around the world live with just one lung.³
• No matter how hard you breathe out, your lungs will always keep about 1 litre of air in your airways. This is what makes the lungs the only human organs that can float on water.⁴
• Oxygen only plays a small part in your breathing. The air you breathe in has 21% oxygen, but your body only uses 5%. You breathe out the rest.⁴
• Children and women breathe faster than men because their breathing rate is higher.¹
• Humans breathe out up to 17.5 millilitres of water every hour.¹

How air gets in and out

When you take a breath, air comes in through your nose or mouth and travels down a tube called your windpipe (you might also hear it called the trachea). This windpipe then splits into two main tubes, one going to each lung. These are called bronchi.

Inside your lungs, these bronchi split again and again into many smaller and smaller tubes, like the branches of a tree. These tiny tubes are called bronchioles. At the very end of these smallest tubes are millions of tiny air sacs, called alveoli (say it like this: al-vee-oh-lie).

These alveoli are where the magic happens! They have very thin walls, and all around them are tiny blood vessels. Oxygen from the air you breathe in moves through the thin walls of the alveoli and straight into your blood. At the same time, carbon dioxide, the waste gas produced by your body, moves from your blood into the alveoli, ready for you to breathe out.

A strong muscle under your lungs called the diaphragm also helps you breathe. It moves down when you breathe in, pulling air into your lungs, and moves up when you breathe out, pushing air out. It’s like a pump helping the air move.

Sources

1. Lung Institute “Never Knew These Breathing Facts.”
2. Live Science “Lung.” 21 Sep 2012
3. Science Kids “Lungs Facts.”
4. Bronchiectasis News Today “8 Curious Facts About Lungs.” 14 Oct 2016