Where’s your horse’s leg?

When I first became Head of Biology at Oxford High, I had a poke around the department and eventually had to ask:

Where’s your horse’s leg?”

“We don’t have a horse’s leg.”

“What do you mean, you don’t have a horse’s leg? You must have a horse’s leg! You can’t teach biology without a horse’s leg! Where is it?”

“We don’t have a horse’s leg.”

“You don’t have a horse’s leg?!?!?!?!?”

“We don’t have a horse’s leg.”

I was shocked. It seemed that they didn’t have a horse’s leg.

Oh well, I thought, that’s quickly rectified, and I started hunting on line for horse legs. By which I mean the bones of a horse leg. This proved harder than I anticipated. None of the educational supply companies stocked horse legs. I eventually found one company that could supply an entire horse skeleton for about £3000, but nothing remotely resembling a single horse leg. Ebay, Amazon, horsesleg.com, all came up short.

I rang the Natural History Museum in Oxford. They were lovely!

“Have you got a horse’s leg?”

“Yes, we’ve got lots.”


“Can I have one?”

“Sure. To borrow.”

“Oh. I want to keep it. Can I have it on permanent loan?”


Damn! It was back to the drawing board.

So I had a think, and decided to track down people who made a living preparing specimens for museums. There aren’t that many… But I eventually made contact with a chap who had lots of good advice. I would need a container for the specimen that could be filled with water and heated – a saucepan or similar. I would need a thermostatic heater. I would need water. And I would need Neutrase


a powerful protease that works best in neutral (hence name) conditions…

Oh, and I would need a horse’s leg.

This last detail seemed a bit of an obstacle, but it proved far easier to source than I imagined.

New to the Oxfordshire area, we had been invited to a lunch party to mingle with local folk and maybe make some friends. I ended up chatting to a man who described himself as a Trainer and Breaker. Of what? Why, of horses, of courses….

Ta da!!!!!!

Well into the second bottle of lunchtime champagne, I said casually,

“these horses you break and train, do they ever, um, die….?”

“Yes, all the time. They break a leg or get an infection or can’t run anymore and they’re put down.”

“Um, the next time, um, one of your horses dies, um….”


“Can I have a leg?”

He was brilliant. He didn’t bat an eyelid. Yes, of course I could have a leg. No problem at all. Front or back?

I told him my preference, gave him my contact details and we parted on good terms.

The very next morning the phone went at about 6am.

“Were you serious about wanting a horse leg?”

“Yes, absolutely!”

“Because we’ve just had one die. Shall I drop it off later this morning?”

“Yes please!”

Long pause.

“It was rather a big horse…”

I didn’t want to let the moment slip.

“I don’t mind! I’ll take it!”

And so just a little later that morning, my wife opened the curtains to look down at our yard, to see a scene like something from the Godfather – a large hessian sack, containing a freshly hacked off horse leg, bleeding profusely into the cobblestones…

He hadn’t exaggerated. It was huge! Nearly as tall as me, and I’m only just under 6′. It must have been a monstrous great thing.

But, key question, how do you set about dealing with a freshly severed horse leg?

First step, remove as much of the flesh as possible. I was sent to the bottom of the garden where I was able to suspend the leg from a tree with bailer twine and use the large kitchen knife to carve off the skin and muscle. This was pretty gruesome and I filled a wheelbarrow with horse meat. A nearby sett of badgers enjoyed a free feast that night…

I now had lots of bones, still held together with scraps of connective tissue and all covered with small bits of meat and tendon. I disarticulated the main bones and put them all into a large metal dustbin I had bought for the purpose. In the larger bones, I drilled a couple of holes…. I then built a little bonfire under the dustbin and heated it to just below boiling. This melted all the fat, particularly the marrow fat which drained from the holes, and formed a disgusting scum at the top of the dustbin….

I dug a hole in the ground to pour the waste water into, refilled the dustbin with fresh water, added the Neutrase and inserted the thermostat, set for 40’C…. and left it for a week.

Oh lordy lordy the SMELL! It was AWFUL, gut wrenchingly HORRIBLE, quite the most disgusting olfactory experience I have encountered. The resulting dustbin soup resembled something they might serve in Hades.

But after a week, as per instructions, I was able to pour off this liquid to be left with…

my long awaited horse leg bones!

horse leg bones

Now why, the patient reader might be wondering, had I gone to all this trouble? What is the educational value of a horse leg?

For that, you’ll have to tune into my next post where I’ll describe that lesson … along with the Tale of the Curious Incident of the Missing Scapula….

thanks for reading!


Whipping up a storm

I’ve been out of the burble-sphere for a while as it’s been a busy term and I’ve been fully occupied with other things, principally two new projects that I’m setting up in school. One, a bee keeping club, is currently in the hive building stage and there’s nothing very exciting to report yet.

But the other is proving to be one of the most fun, interesting, challenging and exciting things I’ve been involved with at school…. and yet it nearly didn’t happen!

It started at a conference I went to in Birmingham last year. One of the other speakers described this amazing project where A-level students were doing original molecular research into Multiple Sclerosis. I was stunned. And immediately wanted to set up something similar. But despite attending the IRIS symposium at the Wellcome Trust HQ in London – amazing building – and finding a small group of students desperate to carry out this kind of research – we could not locate a single research group in Oxford who were interested in this kind of collaboration.

But then, at another conference this October – a school science conference in Tonbridge – I ran into Becky Parker again and she started enthusing about their Whipworm Genome project. I wasn’t immediately sold – it wasn’t the kind of hands-on, micro-pipetting/PCR-ing/gel electrophoresing/fluorescent visualising that I knew my students craved. Sitting in front of a computer scanning a genome for possible genes? I couldn’t see the appeal…

But she took my details, put me in touch with the head honcho at the Whipworm Genome HQ, and I signed up, thinking I might get 5 or 6 of the best Year 13 students interested.

Got that wrong.

I gave an assembly outlining this horrible Neglected Tropical Disease (neglected because only poor people get it, and who cares about them?). I described the project – bioinformatics/genomics – and what it would involve.

Whipworm Genome intro

Note the last slide – a screenshot from the Apollo software involved. I told them not to panic – it was as much a mystery to me as it was to them. I told them we would figure it out together, that I fully expected them to be teaching me, just as my 11 year old son schools me on how to play Clash of Clans….

And something struck a chord. A combination, I think, of:

  • genuine, original research – when they look at a whipworm gene, they are the first person to ever examine it
  • cutting edge technology – gene curating of whole organism genomes is Where It’s At…
  • a challenging and very steep learning curve (more on this in a mo!)
  • a worthwhile project – this might actually make a difference – it’s got immediate relevance
  • it’s online software, so you can do it anywhere you have a computer and internet access
  • looks good on CV/personal statement
  • immediately relevant to A-level…

Whatever it was, I currently have 86 girls signed up. I fully expect some of these to drop out, but not many. The interest and motivation is fantastic.

And it’s been a brilliant learning experience for me. I’ve never analysed a genome before, never curated a gene, never used the Apollo software. So having to do all that, whilst simultaneously trying to figure out how to teach it to students who currently don’t know a huge amount about DNA, has been hugely satisfying.

I started them off with a crash course on DNA

DNA intro for Whipworm Project

– the key bits for this project are understanding the concept of an anti-parallel 5′-3′ double helix; knowing about base pairs; knowing about introns and exons (or CDSs); knowing about UTRs (new to me!); knowing the identify of START codons and STOP codons; understanding that DNA gives rise to RNA which is translated into protein.

That’s a lot to take in for students who don’t know much about the basics of DNA!

But even being familiar with this doesn’t make the Apollo on-line software immediately accessible. So I had to practise with lots of examples and slowly build up a sense of how to do it, what to look for, how to trim or lengthen or adjust the computer gene predictions to what actually matches the evidence.

Because this is the really interesting bit. There are sequences that a computer has identified as looking a bit like a gene. But the computers often get it wrong. The student then has to compare the computer predictions to other data (principally RNA sequence data) derived from living whipworm cells, to see if the prediction matches what’s actually going on in real life…. and then adjust the predicted gene accordingly.

It’s fascinating, compelling and extraordinary. The power of the software, the sheer quantity of data, the elegance of the program, are all strongly addictive. At the moment, we’re just trying it out, running through a section on Chromosome 1 (whipworms have 3 chromosomes) for quality control issues. But just before Xmas, we should get our very own unique section of Whipworm Genome to annotate. Can’t wait!!!


I’ve burbled on this topic before, but only briefly, tucking it at the end of a piece principally about World War 1 Shell Casings and the link to deadly diet drug, DNP…. I want to revisit it, primarily to describe in more detail the lesson, how I structure it, why it works, and use it as an example of how you can turn a non-practical lesson into a process of inquiry and discovery.

See what you think. Better still, let me know what you think!

Year 12. We’ve just about finished Cell Ultra-structure, they’re about to do a homework on Electron Microscopes. I show them this picture…


As ever, Powerpoint for me is a way of projecting thought-provoking images or interactive animations. I never use it to deliver notes – the phrase “Death by Powerpoint” exists for a reason…

So, what is this?

And immediately, they’re engaged. It’s a mystery! A puzzle! They’re all thinking and all have some kind of suggestion. I also use it as a way of encouraging involvement – have a go! what’s the worst thing that can happen? you might be wrong! but at least you tried…

After a round or two of interesting ideas, I start providing clues and someone usually guesses, correctly, that it’s a human embryo on the end of a pin.

I follow this up with another picture of a human embryo, just a bit closer in.

embryo 1

OK, key question, what did this start life as?

Yes, that’s right, a zygote. A single cell. Formed when a sperm and egg fuse…

But that egg, where did that come from?

From the mother. Of course.

And how did that individual start life? Yes, exactly, another zygote! Also formed from a sperm and an egg…

And that egg, where did that come from…?

We start a regress, back through the generation, through ma to grandma to great grandma and beyond.

If we keep going, I ask, where do we eventually get to?

To apes, someone say! Well, OK, yes, a common ancestor of us and apes to be strictly accurate, but no, much further… how far can you go?

They get it. The very first cell… This year, one of them can actually refer to LUCA (Last Universal Common Ancestor).

OK, all very cool and a bit mind boggling and stuff, but how would they describe that very very early cell, in just one word?

We try out a few suggestions before agreeing on “Simple”. This makes sense. Simple things evolve before complicated things. But what does that actually imply? What would this very early, very simple cell, have looked like?

We can’t know, of course, but as a way of stimulating discussion, I show them this:


What do they notice about this cell, particularly compared to the cells they’ve been studying?

That’s right – it’s got no nucleus, no mitochondria, no rough endoplasmic reticulum, none of the complicated internal structures of the rat liver cell that has cropped up so frequently on their interpretive electron micrographs.

So if this isn’t LUCA, what is it? What very simple cells are still among us? Again, they generally get this – it’s a bacterium.

I then contrast it with a more familiar A-level cell…

plant cell

… from which they can cheerfully pick out half a dozen different clearly visible structures.

Which brings us neatly to the key question of the lesson. How did life on earth go from this…


to this…

plant cell                           ?

At this point, I construct a time line on the board, starting with the origin of the Earth 4.5 billion years ago and sign posting it with the key relevant events along with the way (origin of life, 3.5 billion years ago, origin of complicated cells, 1.5 billion years ago, origin of modern humans, 200,000 years ago…). I then use this to add a few notes about the types of cell involved – the simple ones, the Prokaryotes, and what this means, and then the complicated ones, from which all multi-cellular life evolved, the Eukaryotes.

This allows us all to draw breath, before we return to the key question…


We bat a few ideas around. I drop a few visual hints (mainly be juxtaposing the two images and asking them what the bacterium resembles). And eventually someone has the necessary brainwave – did one of them start living inside the other?

Bingo! Endosymbiosis! Lynne Margulis’ brilliant idea that was, as things so often are, ridiculed and rejected….

Lynn Margulis and Endosymbiosis

And finally we can get on to the main exercise where I get them to figure it out for themselves (see attachment above). For if mitochondria used to be free-living bacteria, then perhaps we can make some predictions about what we might expect mitochondria to be like.

I put them into groups of 4 and get them to jot down all the things they already know about bacteria, without looking anything up in their books or their smartphones. Their list will eventually include at least some of the following…

  • they’re really small
  • they have plasmids
  • they reproduce through binary fission
  • they have ribosomes
  • we kill them with antibiotics

From this, I get them to come up with simple 5 predictions about mitochondria, again without looking anything up. Things like, “if mitochondria used to be bacteria, then they should have ribosomes…”

Once they have a list of 5, I let them check their predictions. And lo and behold, they’re right! There is evidence for endosymbiosis, even if it happened over a billion years ago. And they figured it out.

They’re convinced. They’re happy. It’s a successful lesson.

But now contrast it with an alternative lesson plan, perhaps put into a Powerpoint presentation… it might go something like…

“Today we are going to learn about endosymbiosis. Endosymbiosis is the theory that cell structures like mitochondria used to be free-living bacteria. Evidence for this theory comes in the similarities between the two. See the following list…”

It’s the self-evaluation every teacher should carry out before every single lesson plan – am I teaching? Or am I delivering information? The difference, at every level, could not be greater…

Russian roulette…

Just a quickie this week….

It’s Year 10 and the grim effects of smoking. The biology is interesting, though I must admit I prefer to celebrate the power of data to do good things (Richard Doll) and get them thinking about experimental design (how to show a causal link between smoking and cancer?). The following exercise is designed to cover these learning outcomes and doesn’t need much comment from me (though do look at the wonderful quote from James 1st/6th!).

Smoking and Epidemiology and Richard Doll November 2017

But how to convey the sense of genetic Russian roulette that is random mutation?

For this, I came up with the following interactive Powerpoint…

Random mutations in DNA interactive

The first slide just introduces chromosomes and we have a very basic chat about genetics and the idea of coded information.


A mutation, I explain, is just a random change to that information – the key point is, it could occur anywhere….

The second slide indicates 22 loci (the blue circles).

chromosomes 2

I ask a student to pick a blue circle, a locus. Any one they like. Clicking on the blue circle will, 21 times out of 23, take them to a slide saying:

Silent mutation

No effect no person

Clicking on the smiley face takes them back to the second slide, and the locus they selected magically disappears. We talk about the idea of silent mutations. Another student picks another circle, with, one hopes, the same effect.

But at some point, somebody will choose the bottom circle of the two on chromosome 7. Clicking on this circle takes them to this message:

Mutation to onco-gene

Uncontrolled cell division


So I hope they take home the idea of random mutations and that smoking is like playing Russian roulette with your genes, but also the idea that the more you smoke, the more you increase that risk.

Short and sweet – let me know what you think!

Festive Viral Fun

So, what kind of teacher are you?

When Year 11 start Infectious Disease, I always get them to build Jolly Christmas Viruses. There’s quite a variety of cut and stick models easily accessible on-line…

virus model

…and if you photocopy them on to lots of different coloured card and lay in industrial supplies of glue and glitter and pipe-cleaners, you can’t really go wrong.

I do insist that every virus be different. I show them a clip from Secret Life of the Cell (about 15 minutes in) where we see an adeno-virus gain access to the cell using its antigen and a cell receptor (this kind of hinting at the glorious complexity of A-level Biology is all part of my retention and recruitment plan).

And then I put on some salsa music and let them get on with it for an hour…

When they’re done, they attach a bit of cotton thread and we dangle them from the lab ceiling, where they quietly drizzle glitter on innocent students for the rest of the year…


Here’s a not-particularly-special bacteriophage in mid-dangle.

I’ve worked with teachers who utterly fail to see the point of this lesson. It addresses no learning outcomes, it delivers no information, it utterly fails to tick a single learning objective on the specification, it uses up valuable Copy The Notes From The Powerpoint time…. I think they panic because they feel out of control – the students are working autonomously, and this is an uncomfortable feeling if you’re not used to it.


It’s fun.

It’s different.

It’s memorable.

They will do wonderful things – one student produced a virus with a little portrait of Justin Bieber at the end of each antigen – the virus that causes Bieber Fever….

It gets them asking all kinds of interesting and relevant questions.

Because how can something so tiny (a virus to a football is the same as a football to the planet Earth…) and so simple (bad news wrapped in protein) make you ill? Discussion of rabies and smallpox and herpes and AIDS all follow naturally.

Which leads nicely to Immunology. Try my simplified animated Powerpoint as an introduction to Clonal Selection and Expansion…

Immune response


Blow their minds…

Sometimes you just have to amaze them. Go in and say, “have you seen the news today???? They’ve only gone and detected gravitational waves from the collision of two neutron stars!!!! Isn’t that amazing???? What? Neutron stars? Oh, stars that collapsed but didn’t quite become black holes. All the space in atoms crushed down so that a teaspoon of star has the same mass as all of humanity…. And two of them collided! Caused a kilo-nova! Equivalent of 1000 supernovas!!!!! Isn’t that mindblowing?!?!?!? And that’s where all the gold and platinum in the universe is made!!!!! So my wedding ring is made from stuff formed by two colliding neutron stars!!!!”

Of course, being biological burblings, I prefer, where possible, to use biological examples.

Such as some of the experiments emerging from epidemiology.

Heard the one about the mouse?

Conditioned with cherry blossom and electric shocks (almost sounds like a treatment for hair – wonder if it would help it re-grow?). So it learns to associate the smell of cherry blossom with an electric shock, and starts trembling with fear just with the smell of the blossom. Pure Pavlov.

But then let it breed – a nice break from electric shock therapy. And then expose the offspring to the scent of cherry blossom….

The offspring tremble with fear even though they have a)never been exposed to cherry blossom before and b)never had an electric shock in their lives.

That’s incredible. How does it work? We don’t know! But that’s where and why science is exciting, pushing at the frontiers of knowledge and trying to understand the universe better.

Heard the one about the other mouse?

Stick it in a cage with a bigger mouse where there’s nowhere to hide. The smaller mouse gets bullied. Becomes fearful and runty. Doesn’t grow. Stressed and pathetic.

But then pop it in a cage with a female and let it breed. Again, makes a nice change for it.

The offspring are all fearful, runty, stunted, stressed pathetic mice.

Seems like more evidence of epigenetic effects.

BUT!!!! – now you can talk about the importance of experimental design and rigorous controls.

Repeat the experiment, but instead of letting the bullied mouse breed, extract its sperm (don’t ask how) and artificially inseminate the female.

Guess what – when not exposed to Mr Runty himself, the offspring are all perfectly normal. So not epigenetic, but still pretty bloody amazing – the female can somehow adjust her level of maternal investment based on the apparent quality of the male.


I think this kind of thing is so important. Because if you can’t get excited about your subject, why on earth should you expect your students to? And keeping up to date with the latest developments provides a constant supply of amazing stories to inspire them with.

Role-playing Homeostasis

As regular burble fans will know, I use lots of role play in my lessons. Students become molecules, baboons, ship-wrecked survivors, blood-letting physicians and so on. In this lesson, which covers the whole of the Homeostasis topic, they have a wide variety of roles. With a synoptic set of homework questions to follow. Note the props!

The downloadable script is here: Homeostasis Play anonymous version October 2017

(note that you can choose the name of a specific student by using Word replace function to replace Student with a name...)

but for ease of reading, I’ve also included it below.

Student’s Big Day Out

an adventure in the Homeostatic Wonderland of Student’s body

Dramatis personae

  • Student’s brain
  • Student’s liver
  • Student’s pancreas
  • A sweat gland in Student’s skin
  • Student’s kidneys
  • Glucose molecules
  • Insulin
  • ADH
  • Student’s muscles
  • An Enzyme
  • Student
  • Student’s teacher
  • Heart and Lungs


  • Model: heart, lungs, brain, liver, kidney
  • Large beaker – red water
  • Large beaker – yellow water
  • 3 x distilled water bottles
  • Can of Coke
  • Potato
  • Thermometer
  • Torch
  • Weights


You join us at an exciting point in my school day. I’m about to walk down the corridor to my favourite lesson of the week, Biology. Can my body cope with the extraordinary demands that this exercise will present? Or will I die? Let’s find out.

Student’s muscles (pumping iron)

Typical. We do nothing all day long and suddenly we have to work really hard. Contract, relax, contract, relax, contract, relax. Where’s the oxygen? Where’s the glucose? It’s not easy being a muscle, I can tell you, especially Student’s muscle. Phew, it’s getting a bit hot in here…


(very camp) Tell me about it! Here I am, controlling the rate of respiration, producing ATP, basically helping this boy/girl here do her work, and it’s warming up. Doesn’t he/she know I might denature? Just look at my active site! (displays active site) Very sensitive, me. What will he/she do without respiration? I’m the main character in this play, and don’t you forget it.


(yawns). Hmmmm? Whassup? Whassgoingon? Oh, right, it’s the end of Maths. Mmm,  and now I seem to have made a decision to walk along a corridor. Better check on the blood temperature. (dips thermometer into blood). Blimey! It’s gone up 0.1˚C! Time for a bit of action on the cooling front. Ermmm, what do I do? Errm, damn, if only I’d been paying attention in that fantastic Biology lesson, I’d know the answer. Help! It’s gone up 0.2˚C! This could get critical. What do I do?


I’m OK for the moment, but don’t push your luck. 0.2˚C I ask you.


Send an impulse!




Send an impulse! Cor, call yourself a brain? I’ve seen bigger brains in an intestinal nematode. No question who the most important organ round here is.


I agree. No question at all. Look at how complex I am. Look at all the things I control and monitor. I’m responsible for all his emotions and memory and everything! Definitely THE most important organ.


Pah, if I wasn’t here to store the glycogen, heat the blood and break down toxins, you wouldn’t last 5 minutes. I’m the centre of metabolic activity, me, so less of the superiority complex. Every animal has a liver. Very few have a big brain. Check out any Year 8 student.


So what?


Well, put it this way. If I wasn’t around to break down the alcohol in people’s bloodstream on a Friday night, they would be terminally dead before Saturday morning. Anyway, stop prevaricating and send a flaming impulse! We’re all getting warm down here.


But an impulse to where?


A sweat gland, you great wally!


Oh yeah, a sweat gland. (shines torch at sweat gland).

Sweat Gland

An impulse! Hurrah! Let’s get sweaty! (squirts water over Student). Lucky I’m here. All this water will evaporate off his/her skin and he/she will lose heat as a result. How cool is that?!?! (continues to squirt Student)

Enzyme (grudgingly)
Hmmm. Things do seem to be cooling down a bit. That’s nice. But hey, not too much cooling! I’m very sensitive, me.


As she keeps saying. Hope that stupid brain is on the job. We seem to be losing a lot of water.




Oi! Brain! Wake up!!!!


Huh? What now? Honestly, if it’s not one thing it’s another.


(sarcastically) Notice anything?


(defensively). Er, no. (looks at thermometer). Er, yes! We’re back to ideal blood temperature! Hurrah for me!


Notice anything else?


What do you take me for? A biologist? Though now you mention it, this blood seems a bit sticky.


Ta da! Come on, get your osmotic pressure sensor out!


(guilty) Oops! (dips potato in blood and looks at it) Oh no! Now we’re losing water too fast! (looks at thermometer). But we’re still heating up! (shines torch at sweat gland who squirts Student)

Sweat gland

Still sweating! No sweat, sir.


But we need sweat!

Sweat gland

That’s what I mean! It’s no sweat to keep sweating.


Oh, right. (looks at potato). But the blood is getting too concentrated! If the blood gets too concentrated, something horrible will happen. And if I had only done the theory on the Osmosis project back in Year 9, I’d know what!  Help! What do I do now?!?!?


(very French: coughs meaningfully)


Who are you?


Who am I? who am I? I am zee famous ADH, that’s who. Antee, Die-yoo-rettic Hormone.




Releasez moi!




Releasez moi!


But I’m not holding onto you!


Look, you English fool, your father is an ‘amster and your mother smells of elderberries. I shall say zis only once. Send an impulse to zee pituitary gland which is just in front of you. And it will release me into ze bloodstream. Do it! Before your little cells shrivel up and make you even less capable of rational thought than you already are, and I shall taunt you once again!


OK OK OK, here goes. (shines torch at ADH)


Close enough! I am free! (floats along in the blood stream knocks on liver) Allo? Is zis de Kidney?


No, I’m the Liver. Go away!


Ooops, sorry, I shall try again. (bumps into Pancreas). Allo? Are YOU ze Kidney?


Oh go away. My receptors do not match yours.


Let’s try again. ( bumps into Kidney) Oi, Kidney!


(cheerfully squirting water into the bladder)



Stop excreting water!




Coz I tell you to, you dozy organ. We’re losing too much water in the sweat and at this rate he/she’ll be dead from dehydration. Stop excreting water!


  1. (stops squirting water)



Is that it?


I’m afraid so.

Kidney (grumbles)

Very small part for me.


Oxygen! Give me more oxygen! And get rid of this damn carbon dioxide!!!!


(shines torch at Heart and Lungs). Come on, chaps! Work harder!

Heart and Lungs

We canna give her any more, cap’n!


Phew! We’ve stopped! He/She must have reached the classroom.

Heart and Lungs

Thank heavens for that!


(shines torch at Heart and Lungs)

Calm down, sort out the oxygen debt, and then return to resting levels. Right, I’m thirsty.


Of course you are. That’s something else I do.


Hmm? Is the teacher watching? Quick! Let’s drink some coke! (Student swigs some Coke).


(thunders) Student’s surname!! Are you mad! You are deliberately imbibing the drink of the devil! You will suffer tooth rot, mood swings, caffeine addiction and Type 2 diabetes! Put it away this instant!


(meekly) Yes sir. Sorry sir.


(shines torch at sweat gland) You can stop too.

Sweat gland

No sweat no sweat!


Er, yes.


Never mind the sweat! It’s too late! The stomach is full of glucose molecules and we’re going to have big problems here very, very soon!


Yes, everyone knows that you only have a teaspoon of glucose in your blood at any moment. Student’s just drunk something that’s 30 times more concentrated! What’s going to happen?!?!? (picks on non-actor to answer the question).


Exactly! Luckily, I know what to do. Insulin!


(salutes) Insulin reporting for duty sir!


Ah, Insulin, loyal and trusty hormone. You must hurry to the Liver. Travel in the bloodstream. You know what you must do.


(salutes) Yes sir! (hurries off in bloodstream, passing Glucose molecules that are entering from intestine). Cor, look at all this glucose! If this gets much worse, the blood will get too concentrated, and Student will lapse into a coma. Would anyone notice? Hmmmm. But we must still avert the danger! Watch me go!

(reaches Kidney)

Oi, Liver!


I’m the kidney! Sort out your receptors!


Ooops, sorry. I’ll try again. (reaches Liver) Oi, Liver!


Oh, look, a little hormone. What can I do for you, little hormone?


Less of the patronising nonsense, sunshine. You’ve got a job. See all this glucose?




Get it out of the blood! Take it into your cells and do something with it. But do it quickly!


Righty ho. (starts grabbing glucose). In you come, all of you, that’s it, through the membrane, out of the blood. Naughty glucose! See the problem that brain causes? If it hadn’t decided to drink that Coke, none of this would have happened!


Don’t you start again.


Oh don’t mind me. I’m just a liver. You’re the suicidal idiot who dumps all this rubbish on the body. I’m just the poor sap who has to deal with it. (sotto voce) She’d have been much better as a gut nematode. (louder). Right, you glucose molecules, line up! Attention! I’m going to put you into storage. But I can’t store you as glucose because you’ll affect my osmotic balance. Here, link arms. (glucose molecules link arms). Good! Now you’re a molecule of glycogen, and you can stay there until we need you.


What happened to the cooling mechanism? It’s still too hot.


Must be the school’s lack of air conditioning. Get the brain to sort it. Brain! Oh brain!




Oh great. He’s dozed off. What shall we do now?


Wake up! We’re overheating!

Sweat gland

Can’t do anything without a signal from the brain


Wake up!


(smugly) I said this would happen.


I’m melting!!!!! (active site changes shape)


Help! If he can’t work, the body can’t respire!  Check out the 7 life processes!


Ermm, movement? growth? ermmm, beer?


RESPIRATION, you dolt! All LIVING things respire. And we’ve stopped respiring!!!


Bother. There goes respiration. We’re going to die!!!!!