The lungs are an essential organ to all mammals. Today we’re going to find our how lungs work by making a lung model.
The lungs are part of our breathing system which has two functions:
- ventilation – the movement of air into and out of the lungs
- gas exchange – this is where gases are exchanged between tiny sacs called alveoli and the blood.
Under the lungs is the diaphragm which is a muscular sheet separating the lungs from the abdomen. Your diaphragm moves up and down to increase the space in your chest like the balloon at the bottom of the model.
You’ll need
- A plastic bottle
- A straw
- An elastic band
- Scissors
- 2 balloons
- Play dough
Instructions for making a model lung
1. Carefully cut your bottle to about half the size.
2. Tie a knot in one end of one balloon and cut off the fat end.
3. Stretch the balloon around the bottom of your plastic bottle.
4. Put a straw in the neck of the other balloon and secure tightly with the elastic band but not so much that you crush the straw. The air must flow through, so test it with a little blow through the straw to see if the balloon inflates.
5. Put the straw and the balloon into the neck of the bottle and secure with the play dough to make a seal around the bottle – make sure that again, you don’t crush the straw.
Hold the bottle and pull the knot of the balloon at the bottom. What happens?
You should find that the balloon inside the bottle inflates, and as you let go the balloon deflates.
Why does this happen?
As the knotted balloon is pulled it creates more space inside the bottle. Air then comes down the straw and fills the balloon with some air to fill the space! When you let go of the knot the space no longer exists, so the air from the balloon is expelled making it deflate.
Inside the lungs are a network of tubes which allow air to pass though. Air is warmed, moistened and filtered as it travels through the mouth and nasal passages. It then passes through the a network of tubes, eventually reaching tiny sacs called alveoli which are where gas exchange occurs.
How do lungs work?
This fake lung demonstrates how our lungs work. Air is taken in through the mouth and nose, passes down the windpipe and into our lungs. The diaphragm at the bottom of our chest moves down to create more space. As we breathe out the diaphragm raises again. The knotted balloon represents the diaphragm and the balloon inside the container the lung.
More human body science ideas
Create and build a DNA model from candy!
Try this super simple heart rate investigation.
Make your own stethoscope with a cardboard tube, tape and a funnel.
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Liz Burton
April 13, 2012 at 11:39 amVery cool – even if it does make me feel a bit queasy!
Ellie
December 9, 2013 at 5:41 pmI know how you feel.They could have chose a less effective colour.
dinnie
January 17, 2014 at 8:57 pmyea
Sarah Avila
April 15, 2012 at 1:26 amI have made this with my oldest son! It’s really neat; I plan to do it with all my kids when we study anatomy!
ScienceSparks
April 15, 2012 at 1:39 pmI’m so glad you liked it!
Hannah
April 16, 2012 at 10:10 pmVery cool. Now to remember this when Bunny is a little older! My “No Time for Flashcards” post is a look at our week of playschool– http://www.notimeforflashcards.com/
Carrie
April 17, 2012 at 7:05 pmWhat a great demonstration!! Thank you for sharing at Sharing Saturday!! I hope you are having an amazing week!
Pinkoddy
April 18, 2012 at 9:59 amThat is seriously impressive. My get my husband to make one with our 8 yr old.
Emily
April 19, 2012 at 11:16 amThis is excellent, thank you. My son and I have just started exploring science at home and this site is wonderful. I’m so glad you link up to Sharing Saturday, thank you.
Isil
April 19, 2012 at 1:51 pmGreat way to teach science! Thanks for linking up to Kids Co-op.
Alissa @ Creative WIth Kids
April 20, 2012 at 1:28 pmSo Cool! This is the first time I’ve understood how a lung works. Thank you for giving me my weekly science lesson 🙂 Nominated you for a MAD award, btw. Thanks for sharing on Kids Get Crafty! ~Alissa and Maggy
Mama B
April 21, 2012 at 1:11 amI am new to your site and really like it! I pinned the how to make a lung idea to my learning ideas board – what a great idea…can be used in so many ways! Thank you!
ScienceSparks
April 22, 2012 at 9:48 pmThank you for pinning. xx
Aimee
April 21, 2012 at 2:13 amI just wanted to stop by to tell you that this is so awesome it is being featured this week on the The Sunday Showcase Have a wonderful week-
Aimee & Bern
ScienceSparks
April 22, 2012 at 9:48 pmThank you so much. xx
Amy
July 23, 2012 at 3:24 amThis is a great idea! And it would work well to show the effects of smoking too. Use a wide straw (like one from McDonald’s) to fill the lung, then feel the difference in how fast or easily the lung fills using a narrow straw (like a tiny one for stirring coffee). I will for sure be doing this demo with kids! Thanks!
ScienceSparks
July 23, 2012 at 6:48 amFab. I’m glad you liked it.
tracey
January 28, 2013 at 11:58 pmYou have to use a very sturdy water bottle for this project. My son and I went through many balloons trying to make it fit over a standard water bottle…..we ended up using a Snapple drink bottle because the plastic is stronger.
Missy
October 21, 2013 at 2:30 amThis looks great! We’ll be trying it this year when we learn about the respiratory system in our homeschool! Thanks for sharing!
Ellie
December 9, 2013 at 5:44 pmI’m making this for a science project and I hope that I do it right!How clever!It must have taken a while to think of that.GREAT IDEA!
lovely
January 24, 2014 at 8:45 amIt is so nise but we have two lungs.but you have shown only one.
Becca
March 24, 2014 at 11:40 pmGreat demonstration, I just wanted to correct the following statement:
“This demonstrates how our lungs work. Air is taken in through the mouth and nose, passes down the windpipe and into our lungs. The diaphragm at the bottom of our chest moves down dot create more space.”
The diaphragm is the muscle that makes breathing happen. As it contracts and spreads flat in the abdomen, it creates a vacuum that draws air into the body. This model demonstrates how a vacuum works.
Leila
August 29, 2014 at 2:02 pmThis is so great. I teach flute and was looking for some kind of demo – this is perfect – if I can get mine to work as well as yours does 🙂
Aasiyah
March 12, 2015 at 3:48 pmAwesome experiment! Did it with my school and didn’t understand the science bit…l thank you!!
Aasiyah
March 12, 2015 at 3:50 pmSuggestions: Instead of using a balloon as the lung, you can cut off the fingers of a doctors glove and Sellotape it to a y tube. It’s much more accurate
Rose
April 26, 2015 at 12:15 pmIt can be difficult to find plastic bottles that hold up to having a balloon stretched across the bottom. They all seem too thin. Can anyone suggest brands?
Emma Vanstone
April 29, 2015 at 10:28 amI’ve redone this recently and used a diet coke bottle, but I did reinforce it with some masking tape.
Esther
July 19, 2019 at 9:20 pmUse a strong plastic clear cup with a lip at the bottom. The balloon fits nicely over it.
saurabh
June 7, 2015 at 2:09 amit is very easy to understand how they have discribe their eperiment i thank science aparks for this
alexis
May 13, 2016 at 8:19 pmawesome!!
jess
November 23, 2016 at 5:36 pmThis s a great experiment, we did it with 10 year olds and really got them thinking – easy and clear – thanks for the clear instructions 🙂
Just in case you want to know – few spelilng errors noticed – of not off and ballon and bow not blow.. x
Emma Williamson
November 25, 2018 at 8:22 pmThis looks like an absolutely perfect model for some school activities. I’ll definitely use it with my kids.
MsWiz
November 28, 2018 at 6:09 pmMust have a strong 2 liter bottle. Many are too bendable
Ressenia
January 28, 2019 at 1:24 pmThis project is so cool I’m doing one for my project
PrimaryLearning.org
October 23, 2019 at 1:33 pmWow! Thank you for sharing such a great activity! I’ll share it on my facebook page.