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Lung Model

Public summary: 

Use our interactive model to find out how we breathe.

Working model of the lungs with diaphragm and rib cage.
Useful information
Kit List: 

Lung model
Standard CHaOS power pack plugged in to mains supply.

Packing Away: 

The hand packs together with the lung model and handy engineering for storage. The box is in three pieces, first place hand down and fold at the hinges, using the hook and eye to secure at right angle. The fingers of hand should bend upwards however you may need to manually position hand to get this to fit. Then place the non-lung piece on the opposite side, tuck the strings through the provided gap and fasten the two small carabiners. The hinged triangle can hold tuperware and the slot can hold the folder for handy engineering. Then place lung on top, ensuring it locks downwards. Fasten the large carabiners on top. Carrying the box using the handles on the bottom, either with two people also using a hand to prevent tilt or one bear hugging.

Frequency of use: 

A model of the lungs to show how the diaphragm and rib cage cause the lungs to inflate and deflate.


Begin with general concepts…

1. Ask what your lungs are for – answer is usually breathing
2. Get across the concept of 2 functions – getting the air into your lungs, then getting the oxygen from your lungs and into the blood – then say how the model show the first of those.

Then onto how the model works…

1. Get them to name the different parts of the model = ribcage and lungs
2. Get them to take a deep breath, and describe what’s happening to their chest as they do it = getting bigger
3. Why is it getting bigger? This is where the confusion usually sets in, because a lot of kids think that the lungs fill up with air and push the chest out. So, need to say that the lungs are just bags, can't do anything on their own to get the air in
4. So, the chest is getting bigger because the ribs are moving up and outwards (moved by muscles)
5. Also, when you want to breathe in, you move the diaphragm, which is the big muscle underneath the ribcage – point it out on the model.
6. So what happens when we do these 2 things on the model – I usually pull the ribs up, and get them to pull the diaphragm down. What happens? Balloons (lungs) fill up with air, and all we’ve done is move the ribs and diaphragm.
7. Why do they fill up? When the ribs are moved up and out, and the diaphragm pulled down, do we have less or more space inside the chest = more space. When we have more space, something has to fill the space, but what? = Air, which comes into your mouth, down your throat, and into your lungs, makes them bigger, to fill up the extra space. (You can talk about pressure if they're old enough to understand, or if they've done the vacuums experiment!)
8. Then breathing out – ribs move down and inwards, and diaphragm moves back up – do it on the model – what happens? Balloons (lungs) get smaller, air is coming out of them. Why? Have made less space inside the chest, so no space for the air in the lungs, so air forced out of lungs.
9. So overall, breathing is all about changing how much space you have inside your chest.

General stuff:

– Point to parts on model and on yourself while talking.
– The annoying thing about this model is that it’s very hard to keep the bags airtight. That’s what the pump is there for, you shouldn’t need it on all the time put probably in between explanations.

Additional stuff:

1. Gas exchange
- Why do we breathe? = to get air into our lungs. Why? What’s in the air that we need? = oxygen
- Where does the oxygen need to go? = all over the body to all our cells. And why? = to make energy
- How does the oxygen get around the body? = travels in the blood (attached to red blood cells)
- So, the oxygen is in the air, and needs to get into the blood – how? = travels down tubes in the lungs to the edges of the lungs, into little sacks. (lung is big sack made up of lots of little sacks = alveoli). Next to the little sacks are blood vessels carrying blood. Oxygen travels from alveoli into the blood and gets carried away to the heart, which pumps the blood (and therefore the oxygen) around the body
- Also, in the alveoli, a gas comes out of the blood, a gas we don’t need = CO2, which gets breathed out

2. If things go wrong
- PNEUMOTHORAX - When the lung is punctured (e.g. by broken ribs) so it can't take air in. Talk about how even if one lung is down, the other can still work.
- ASTHMA - Ask if they have it themselves or have friends who have it? The tubes get smaller, making it harder to breathe in and out. Show this by putting your hand over the top of the trachea and restricting the opening and asking them to breathe in. Could talk about how inhalers have medicine in that makes the muscle around the tubes relax, so they get bigger and more air can get in.
- HICCUPS - show that the diaphragm is right above your tummy. If you eat hot food too quickly sometimes it can irritate the diaphragm leading to involuntary contractions. Other times it can be spontaneous.

Risk Assessment
Date risk assesment last checked: 
Mon, 27/01/2020
Risk assesment checked by: 
Date risk assesment double checked: 
Mon, 27/01/2020
Risk assesment double-checked by: 
Beatrix Huissoon
Risk Assessment: 

Model of ribcage and lungs to show breathing.

Hazard Risk Likelihood Severity Overall Mitigation Likelihood Severity Overall
Wooden frame Splinters in edges of wooden frame. 3 2 6 Discourage people from handling the wooden frame, look for any rough edges and apply sandpaper/tape as necessary.
Call first aider in case of injury.
2 2 4
Pump Electrical hazard from electric pump. 2 2 4 Pump is 12V so this is negligible.
Make sure power supply is PAT tested.
In case of accident, switch off the pump and call a first aider.
1 2 2
Holding breath Dizziness from holding breath or breathing too heavily. 2 1 2 Warn children not to breathe too heavily or hold their breath. Call first aider in case of injury. 1 1 1
This experiment contains mains electrical parts, see separate risk assessment.