Your lungs

Together, your two lungs are one of the biggest organs in your body.  They sit in the middle of your torso, underneath your rib cage.  Your lungs are quite delicate - they would look like soft, pink, rubbery sponges if you could see them!  The set of 12 ribs you have are connected to your spine and come all the way around to the front to protect your lungs from damage.  They are not the same size as your left lung has to be a little bit smaller to make room for your heart to fit into your chest, otherwise it would be pretty squashed!    

Every time you breathe, your lungs take in air.  To do this, you ribs and diaphragm work together to make sure there is enough room for your lungs to expand and contract.  Your diaphragm is a very strong muscle that lies just below your lungs.  When you inhale (breathe in), your diaphragm contracts (squeezes tight) and goes from a dome shape to a flat shape.  As it moves down, it has to push some of your intestines out of the way, but you don’t feel that!  At the same time, your rib cage moves outward, making the space for your lungs to expand as large as possible.  The air you breathe moves through your lungs (learn about all the different part of your lungs below) and fills up your alveoli, your air sacs.  Oxygen moves from your alveoli to your red blood cells through the walls of the capillaries that cover the alveoli.  At the same time carbon dioxide is removed and you just breathe it out.  Your red blood cells then carry oxygen to every cell in your body!

When you exhale (breathe out), you get rid of the carbon dioxide waste that your red blood cells have taken from all the cells in your body.  Your diaphragm relaxes and returns to its dome shape making the space for your lungs smaller.  At the same time, the muscles between your ribs (your intercostal muscles) relax and air is pushed out of your lungs.  To feel this happen, put your hand on your chest and take a deep breath.  Can you feel your chest get much bigger as you inhale and smaller as you exhale?

You lungs look like sponges on the outside but inside they are a whole network of pipes and tubes!  Air comes from your nose and mouth down your trachea, your windpipe.  This breaks into two main tubes called the bronchi, one of which goes to your right lung, the other of which goes to your left lung.  Each bronchus (one of the bronchi) is like the branch of a tree – it has lots of little twigs coming from it.  These are called bronchioles and they are about as wide as a hair!  Right at the end of the bronchioles are your alveoli, your air sacs.  They are so tiny that almost 600 million fit into you lungs!  Each one of these is covered in absolutely tiny tubes called capillaries which is where red blood cells, one cell at a time, swap the oxygen you inhale for the carbon dioxide waste you want to get rid of. 

Your lungs allow you to do more than just breathe – without your lungs you couldn’t talk or sing!  At the very top of your trachea is your larynx (sometimes called your voicebox) that contains your vocal cords.  These make sounds as the air from your lungs makes them vibrate.  If you blow out a lot of air from your lungs you will make a big sound like a shout.  Take a big breath and try to count as high as you can in a normal voice.  What number do you reach before you have to take another breathe?  Now, try it again but shout the numbers.  What happens?  It takes lots more air to shout so you probably won’t get as far!

Your lungs are very precious.  Your body tries to protect them as best it can – it has tiny hairs called cilia inside your nostrils that trap and small bits of dust and some microbes.  Anything that doesn’t get trapped there can get stuck in the mucus on the inside of your trachea.  There are lots of things you can do to keep your lungs healthy.  The most important one is to exercise every day.  This makes the muscles around your lungs work harder and makes your lungs ‘fitter’!  It’s a very bad idea to breathe in things that can harm your lungs, like smoke, chemicals or things like glue.  If you are using glue or if your parents are using things like paint or chemical cleaners at home, remember to open a window and get as much fresh air into the room as possible.

Normally you don’t have to think about breathing because it is an involuntary function.  Breathing happens even if you don’t think about it!  It is a very strong function, if you try to hold your breath, when the oxygen in the air has run out, your body will make you take a breath!  Sometimes people have problems with their lungs that can make it difficult for them to breathe.  If you have asthma, there can be times when the tubes in your lungs get clogged up with mucus or tighten up.  Your doctor can usually give you something to make this better though.  The best advice though is to do the best you can for your lungs, especially if you have a condition like asthma….don’t smoke!  Remember:

Be smart – don’t start!