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Giant intestine model

Introduction
Public summary: 

Everyone knows that your intestines are long, but how long is long? Find out with our scale fabric model, and you might be surprised!

Functional model of the intestine
Useful information
Kit List: 

Model of the intestine, which can be used to explain the digestive process to children.
May also include tube made from chopped-off tights and a smooth plastic ball.

Packing Away: 

Packs into Organ Vest box. DO NOT PACK INTO THE LARGE 'BORIS' BOX.

Frequency of use: 
4
Explanation
Explanation: 

ACTIVITIES:

- show the model to kids, let them feel it and ask them to guess what they think it may be
- illustrate the length of the intestine: get a kid to stand up and use the model to illustrate how long the intestine actually is (you can hide it in the bag and give the child one end to gently pull out and walk across the room until the whole thing is stretched out, if there's enough space and the child is sensible about it) Get them to imagine that such a long tube is actually rolled up within the small space of their tummies...
- get them to feel the inside- there are ridges. You could use this to discuss surface area (i.e. “what would happen if all these ridges were smoothed out?”)
- Use the plastic ball as a bolus of food and squeeze it through the tights tube to describe peristalsis.

THINGS TO TALK ABOUT:

- basic theory of digestion, i.e.”what happens to the food once we’ve eaten it?”
- what you need to make digestion effective: surface area of the intestine; how to increase surface area (ridges, length of intestine- use model to demonstrate)
- Things that can go wrong: diarrhoea, constipation, etc.

TIPS FOR DEMONSTRATING:

The idea is to get the kids involved as much as possible. The best way to do this is by using the model as much as possible when you explain things. Let the kids play with it as well- and get them to figure out things for themselves.

BASIC PROCEDURE AND EXPLANATION:

What do we use our intestines for?

- Our body is made up of loads of small factories, called cells
- What do they think these factories need? – Food (That’s why we eat...)
- However, the food we eat is very big and these cells are really small (so small that you can’t usually see them with the naked eye!)- so the food needs to be broken down
- What do they think breaks down the food? Talk about teeth, stomach, also your intestine
- The pancreas secretes a special liquid that breaks down the food (If the kids are older, they will often have heard of enzymes, so you can expand on this point as much as you- and they - like...)
- So, once the food is broken down, how does it get to cells in the body? Via the blood (for young kids: the blood is a bit like a lorry- it can pick things up and bring them somewhere else)
- The intestine is the place where the food gets taken up into the blood (for older kids, talk about absorption etc.)
- How does food move through the intestine? Use the ball and tights tube to explain peristalsis - there are muscles in the intestine walls that contract to squeeze the food along (use your hands to represent the muscles)

What makes the intestine so good at what it does?

This point is all about absorption and how you can increase the latter by increasing the surface at which it can occur.

For young kids:

Get them to imagine how long the intestine is by using the model. Can they imagine that such a long tube is actually folded up within their tummies (see activities)? So there is a lot of space for the food to get into the blood...

For older kids:

Talk about the length of the intestine as before. Also get them to feel the ridges inside- what do they think would happen if they were all smoothed out? Just for reference, the surface area of the small intestine in an adult person is about 250 square meters – that’s about the same size as a tennis court! How can such a large area fit into our tummies- by folding it up (so all the ridges are folds of the intestinal wall...)

What happens to the food we don’t absorb?

It moves through the intestine and leaves our body as poo- small kids often find this strangely fascinating.

OTHER THINGS TO TALK ABOUT:

- There are two types of intestine (small and large)- they have different functions (parents may ask you about this.)
- Things that can go wrong: diarrhoea, constipation, malabsorption, inflammatory bowel disease etc... see below for ideas:

Diarrhoea – ask who knows what this is?! It’s watery, frequent stool. Very important to kids in developing countries especially – losing so much water (and you can lose blood too – this is called dysentery, which happens with Shigella and Amboebiasis) can be fatal. With cholera you are losing so much water so quickly that it is pretty much literally a battle to give the patient enough water. Common agents – E. Coli 0157 (the E Coli K we have on display is entirely safe though), Salmonella. Both are bacteria. Protozoa (one-celled, primitive, parasites in this case) – eg. amoeba and giardia, are much commoner in the third world. Viruses can cause disease, most commonly in kids, rotavirus being a common one. Norwalk virus causes diarrhoea and vomiting on cruise ships, calling for impeccable hygiene standards.

Older kids might understand the principal of isotonic drinks for rehydration – the ions are needed because so many are being lost, and the water enter cells more quickly due to osmotic attraction and as some ion channels co-transport water. Explain that ions are chemicals like sodium, chlorine, and potassium, and that they spread themselves out in the body into all the cells, with water following them. Ask them if they think it’s important that you keep your cellular ions at a constant level. Ions are lost into the intestine because inflammation at its mucosal surface makes it leaky.

Malabsorption – What if a surgeon cuts out half your small intestine because it got damaged in a skiing accident or whatever? Do you think your intestine will work as well? What do you think happens if your villi are destroyed? This is what happens in celiac disease – it is an inappropriate immune reaction to gluten in the diet. The patient (usually a child) becomes thin and malnourished, slows down their growth and can become deficient in micronutrients, eg. vitamins, which are usually absorben in the small intestine.

Villi are also destroyed in Inflammatory Bowel Disease (these diseases are Crohn’s disease and Ulcerative Colitis). Ulcerative colitis tends to affect the large bowel almost exclusively, decreasing its ability to absorb water. Therefore someone with Ulcerative Colitis will get watery stools. The tissue gets so inflamed (or I guess you could say “attacked” to younger kids) that it bleeds, which can be noticed in stools. Crohn’s can affect the small intestine and cause malabsorption of lots of nutrients, carbohydrates, and lipids.

We mentioned that the pancreas makes enzymes – I like to describe them as being like tiny scissors which chop up the smallest nutrients up into a form which they can just nicely be absorbed into villi. If someone’s pancreas isn't working properly (eg. it gets clogged up in cystic fibrosis, or if they have a gallstone obstructing its outflow) they can’t absorb a lot of things like lipids, proteins and fat-soluble vitamins (A, D, E, K).

Risk Assessment
Date risk assesment last checked: 
Fri, 25/01/2019
Risk assesment checked by: 
Matt Worssam
Date risk assesment double checked: 
Sat, 02/02/2019
Risk assesment double-checked by: 
Conor Cafolla
Risk Assessment: 

Giant Model of the Intestine

Hazard Risk Likelihood Severity Overall Mitigation Likelihood Severity Overall
Tube Risk of strangulation if model/tights tube is wrapped around neck. 2 5 10 Supervise children carefully and do not allow them to wrap model around neck. Call a first aider in case of accident. 1 5 5
Stretched model Risk of tripping and falling if the child runs across the room to stretch the intestine out (especially if stopped suddenly by reaching the end of the intestine) or from using the model as a skipping rope. 3 2 6 Supervise child carefully, only allow them to walk (not run) across the room and do not allow it at all if there is insufficient space or the room is busy. Call a first aider in the event of injury. 2 2 4
Plastic ball Risk of tripping on escaped plastic ball. 2 2 4 Only have one ball out at a time and keep an eye on where it is. The ball is large enough not to be a choking hazard. Call first aider in case of injury. 1 2 2
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