The doctors take a close-up look at how the eye works, and Dr Chris finds out what body fat does by looking at some of his own under a microscope.
Browse content similar to Episode 3. Check below for episodes and series from the same categories and more!
He's Dr Chris.
And he's Dr Xand.
And, yes, we're twins.
Do you know how brilliant your body really is?
I'm getting better.
Well, we're going to show you.
Oh, there you go.
In this series, we'll be pushing our bodies to their limits...
..by doing extraordinary experiments on each other.
This is my sick.
To uncover what goes on inside...
Here we go. Yum, yum, yum.
Ewww! That just came out of my ear.
From the bizarre...
-Could we get a sample of your snot?
..to the incredible.
So now I'm seeing things.
It's time to find out what you're made of.
Chris? Chris? Chris?
-Coming up... BOTH:
-..on operation ouch.
We take a closer look at our peepers.
Wow, that's amazing.
Chris finds out why too much fat is bad.
This yellow stuff is from my tummy.
And why is this guy pulling this face?
All will be revealed, but first...
Medical teams always expect the unexpected.
But no-one was expecting this.
In accident and emergency, ten-year-old Iman
has come in hobbling with, well, he's not quite sure.
I had this rash yesterday that made all my hands
and my legs swell up, and now it's spread for some reason.
Ooh, it's looks serious, but nice socks.
Has this ever happened before?
No, first time. First time.
This is the first time.
Ah, OK. First time, got it. So, how did it start?
Iman was at school in art class.
-Oh, nice sculpture, Iman.
He's got a real talent.
Anyway, just as he was adding the final touches to his
masterpiece, he looked down to see his hand swelling up.
Oh-oh. This doesn't look good.
And it didn't stop there.
It turned into a rash that spread around his body and his
joints became swollen and sore.
The rash has now spread and it's hurting all
the joints on my body like my legs and my ankles and my elbows,
my back and the back of my head as well,
but not really my shoulders.
Well, that's something.
But with a mystery illness at large, Iman's mum and brother have brought
him to hospital to find out what could be causing
his strange symptoms.
This needs to be looked at urgently.
Enter Dr Morag Turnbull.
Nope, she's not playing a tune on his tummy.
She's giving him a thorough examination.
-Ow, that hurts.
-That hurts. Sorry, sweetheart.
I'm really not trying to hurt you.
-That hurts as well.
-Gosh, it just hurts everywhere, doesn't it?
I think what he's got is something that we call HSP, OK?
It stands for henoch-schonlein purpura.
So go on then, Doc, tell us more about it.
What it is, is it's like an inflammation of the blood vessels.
It's something called vasculitis.
You can get this condition after a virus and the inflamed blood
vessels can cause a bruise-like rash and swollen joints,
which can be painful and make it hard to walk.
Ow, ow, ow, ow!
His joints are obviously very painful.
He's not really able to stand, so he's going to need to stay
in hospital until we can get on top of his pain a bit better for him.
Later on, the doctors start to worry that Iman may have something
much more serious.
I think there's a small chance we're dealing with meningitis
because that rash can look like that as well.
So, we'll see how Iman gets on soon.
And now to our lab, where we do incredible experiments...
Oh, it's disgusting.
..to show you how your body works.
It's not pretty to look at, but it is brilliant stuff.
Just don't try anything you see here at home.
Today, it's all about our peepers.
-Your eyes are amazing.
-Ooh, thank you, Chris.
Actually, a lot of people have told me that my...
Not YOUR eyes, everyone else's eyes.
In fact, your eyes can move over a 100,000 times in a single day.
Now, we know that our eyes come in all sorts of different colours,
but if I look into Chris's eyes...
If I look into Chris's eyes,
all I can really see is the coloured bit, the iris and the black
hole in the middle the pupil, but there's a lot more going on.
It's time to delve a little deeper.
This is my digital opthalmoscopic slit lamp.
It's Chris' eye camera.
This will let us look at Xand's eye super close up.
Wow, that's amazing. So, this is Xand's eye.
Now, the coloured bit of the eye here is called the iris
and the colour of the iris depends on the amount of pigment in it.
Xand's got a brown iris, which means he's got lots of pigment
and people with less pigment have blue or green,
lighter coloured eyes.
And the iris is a ring of muscle surrounding the pupil,
and the pupil's black, because it's a hole going right
through to the back of Xand's eyeball.
Your iris and pupil work together to help you see and to show you how,
Chris is going to use this torch,
which is specially made for looking at eyes.
I'm going to shine it into Xand's eye and you'll see his eye
will detect the extra light and contract the pupil.
When I take it away, there's less light
and the pupil gets bigger again.
This is what happens when you go to a dark place like a cinema.
Your iris opens your pupil right up to let in as much
light as possible so that you can see, but if you go to a bright
place, like a sunny beach, your iris closes your pupil right down
to let in less light, because you don't need all that light to see.
Now, I want to show you even more about the eye,
but the only way I can do that is by taking one out and chopping it up.
Don't worry, Xand, I'm not going to chop up YOUR eyes.
I got some from the butchers to help us with our experiment.
-This is a pig's eyeball.
What do you call a pig with no eyes?
That's really bad.
Now, this pg's eyeballs are very similar to human eyeballs
and to show you what's going on inside, we're going to cut one open.
Obviously, we're trained up to do this.
We need to get the lens out because it does something really brilliant.
Oh, there you go. Look at that.
That went really well.
Now the lens receives all the images and sends them to the retina.
And the retina completely covers the back of the eye,
so it's a bit like the sensor in a digital camera.
It captures the image
and then sends the information to the brain for processing.
But, just to make things a little more complicated,
when the image lands on the retina it's upside down.
And that's because light rays bounce off everything you're looking at,
travelling in straight lines.
But your lens is curved, so you can focus on different objects.
When the straight lines hit the curved lens, they bend and
the image hits your retina upside down.
And we can prove it.
I've taken the lens out of this eyeball.
I want you to look through it and tell me what you can see.
Yeah, you're upside down.
Now we appear to be upside down and this is what's
happening inside your eye, but if the retina receives the information
upside down, why aren't we seeing the whole world upside down?
Well, the answer is that when your brain receives the upside down
image, it cleverly flips it over, so the world seems the right way up.
I said it cleverly flips it over, so the world seems the right way up.
Better late than never.
is a place to have fun...
..but it's also a place of danger.
You could get hit on the head by a stick thrown for a dog.
Get dazzled by the sun on a very hot day. Nicely sorted.
Or make your scrubs really dirty and your mum very cross.
-One safe thing you can do is play frisbee.
Ooh! A minor injury.
Still, now that he's hit his head, how shall we treat him?
I didn't hit my head. YOU hit my head.
I'm certain the first one is a bad idea,
but I'd like idea of going on the swings and roundabouts.
Well, the correct answer is C.
Putting something cold on it, like frozen peas, reduces the pain
and swelling. But if you feel sick or dizzy, tell an adult.
-That's looking good, Chris. Much better.
-Yeah, much better(!)
A BIRD SQUAWKS
Do you want some peas for that?
So, if you get bump on the head, put something cold on it to
reduce the swelling - not bird poo.
If you ARE worried then tell an adult.
We've got some incredible body tricks for you to show your mates.
Want to fool your friends into thinking they're falling
through the floor? Well, we're going to show you how.
So we got a really good trick for you.
Xand, I want you to lie on the ground.
-OK. You comfortable?
-I'm very comfortable.
So, Xand, I want you to give me your feet
and I'm going to make your feet feel as if they going through the floor.
-No, you're not. This floor is solid.
-Give me your feet.
These feet are disg... Can anyone else smell Xand's feet?
Xand, close your eyes and I'm going to slowly,
slowly lower your feet and it's going to feel like I've got
these guys to dig a hole under your feet.
They digging holes? I can't hear any digging holes.
How close do you think your feet are to the ground?
-Probably about ten centimetres off the ground.
'More like 50 centimetres, but let's keep going.'
OK, they're right about to touch the ground now. 'No, they're not.'
Whoa! They're going through the floor. Whoa! Whoa!
'His feet haven't even touched the floor yet,
'but Xand thinks they're falling through it.'
Oh, that's really weird, they're through the floor.
'Time for this lot to have a go.'
'So, why do your legs feel like they've gone through the
'floor when they haven't?'
It felt like when you was laying down like,
all the blood was like draining from your lower part of your body,
so it felt like your legs were getting numb.
Well, Olivia's on the right lines, but there's more to it than that.
When Chris held my legs up, the nerves in my joints relaxed
and stopped telling my brain where my legs were.
And having my eyes closed meant that, when he lowered them again, my
confused brain tried to work out the position of my legs but kept getting
it wrong, and that's why it felt like they'd fallen through the floor.
When it was nearly touching the floor,
it felt like I was really under.
Try it yourself and see if you can feel it, too.
Earlier, we saw Iman with that mystery rash.
Let's see how he's getting on.
Back in Sheffield, Iman has spent the night in hospital after
coming in with a mystery illness.
He'd been at school in his art class when, all of a sudden, he
looked down to see his hands were swelling up and a spreading rash.
After being diagnosed with HSP, where your blood vessels
become inflamed, he's been receiving pain medication to treat his
sore and swollen joints.
How's he feeling today?
A lot better than yesterday.
I think I might be able to stand up, but not yet walk.
Well, it's a step in the right direction.
Well, he's not stepping quite yet, Xand, because just as things
are looking up, there's been a new development.
Someone at Iman's school might have meningitis, which is contagious.
Because of this, consultant Judith Gilchrist is on the case.
I think, although it's 90% sure it's HSP, I think
there's a small chance we're dealing with meningitis,
because that rash can look like that as well.
Also, Iman's GP gave him antibiotics a few days ago,
which CAN make meningitis look like HSP.
He's actually had a couple of days of antibiotics already
and there's been a possible contact with meningitis at school.
We may be dealing with a partially treated meningococcal infection.
So, basically, he needs to stop in for at least another two days
and we're going to put a drip into the back of his hand and take some
more blood tests, and we'll start him on some intravenous antibiotics.
Once Iman's handed over some of the red stuff,
it's off to the lab for testing.
But it will take 48 hours to get the results.
In the meantime, Iman just has to wait.
Two days later and our patient seems to be on the mend.
A lot better now. I could walk.
I can reach the lavatory right now.
My legs still hurt, but I can still reach it.
He might feel better, but he still has to get the results from
his blood tests and they're in.
I've got some good news for you.
You're blood cultures are negative, so you can go home.
It's great news. Iman's blood tests show he doesn't have meningitis.
I'm so pleased.
Finally, I'm going home. Yes!
So it is HSP after all,
which will clear up all by itself in a few weeks.
At least for now he's got a spring back in his step.
Still to come, we show you how your body heals itself after a burn.
There's an infected finger in accident and emergency.
My finger's got yellow pus in it.
Nice. And yep, that needle is going to suck out my fat.
Xand? Where's Xand? Xand said he'd do this.
Now, did you know that the average human head
weighs as much as a watermelon?
That's amazing and so's this.
OK, Xand, I've got something for you.
Can you guess what makes this man amazing?
Wow, he doesn't look happy.
-Is he the angriest man in the world?
-He's not on the toilet, is he?
This is John Evans.
He's a world record holding head balancer.
He's balanced a washing machine and a fridge, a car
and even Dr Who's TARDIS on his head.
What's he going to balance for us?
-20 tubs on a large metal frame.
I THINK that's amazing.
It is, Xand, and here's why. He's carrying on his head,
the weight equivalent of 20 bags of sugar
or 500 lemons, or one seven-year-old boy.
John's held more than 40 world records for balancing all
sorts of things on his head. And when it comes to competitions,
he really gives it everything he's got.
Oh, I've done tremendous things.
Two girls on bicycles, 98 milk crates all in one time.
So, how does John's amazing body do this?
Well, the secret is his massive and powerful neck.
Where as your average man's neck is 40 centimetres around,
John's comes in at a whopping 54.
That's the size of Selena Gomez's waist and nearly twice as big
-as your neck.
-Wow! That's big.
But the real power, though, comes from the muscles inside.
There are five major muscles in the neck, but the heavyweights
are the trapezius muscles at the back.
I do have the strongest neck in the world.
It's as solid as concrete.
OK, I'm sold. That's amazing!
Your body can need mending in all sorts of ways and we're going
to meet some special teams that are trained to fix you.
I absolutely love swimming and this is a really cool swimming pool,
but it's not an ordinary swimming pool.
We're in a hospital, and for some patients,
this water is like medicine,
but we're not going to drink it.
This pool is for hydrotherapy,
a type of exercise in water that helps people like nine-year-old
Jay who has arthritis.
So, Jay, can you tell me why you're coming here?
I've got arthritis in my knees and my feet,
and sometimes they're sore and stiff.
So, if you're just running around normally, do your legs hurt?
-And does it hurt when you're moving around in the swimming pool?
-Is it fun as well?
Treating Jay is physiotherapist Amy Robinson.
So, Jay needs to exercise to keep his muscles strong to keep
flexible, but why can't he just do that on land?
Why does he need the pool?
Well, in the pool, because the water is really warm,
it's like having a really nice, hot bath.
It relaxes all the muscles and that's really good for pain
because, if the water is quite deep,
it takes away a lot of the weight on the joints as well.
Jay spends half an hour every week in the pool doing lots of
different exercises and games.
So, what's so great about exercising under water for Jay
is that the water provides resistance, like
if you think of how hard it is to move under water,
it's really good exercise.
But the water also supports his body, so it's less painful.
Keep going, Jay!
That's it. Well done.
So all these exercises, they're hard work,
but they're quite gentle and soft on the joints.
In the mornings, Jay's joints can be so sore and stiff it can take
him two hours to get up and moving, but regular hydrotherapy
makes a real difference.
So, how you feeling now, Jay?
More relaxed, a bit less sore and it's easier to move around.
Really good. Well, look, thank you very much for having me today.
High five. Aww!
This next boy may be accident prone,
but his body is brilliant at mending itself.
Just like yours.
# If there's a bone to break, he'll break it
# If there's a wound to graze, he'll graze it
# If there's an ankle to sprain, he'll sprain it.
# He's the unluckiest kid. #
Mmm, a nice mug of hot coco. Oh, dear.
When you burn yourself, the extreme heat cooks your skin,
damaging the top layer of skin cells.
The damaged cells trigger an alarm inside your body and it sends
in your immune system to clean up the mess.
First, it flushes the area with a load of new blood full of
white blood cells. This makes the burn site go hot and red.
These white blood cells remove the damaged skin by eating it - yummy.
Then there's a rush of plasma.
This creates a blister to protect the area.
Meanwhile, below, new skin cells are being born all the time,
making their way to the top.
So, don't be tempted to pop that blister, as it's doing an
important job protecting the new skin.
Oh, but it's so satisfying!
Yes, Xand, but you could get germs in there.
Your body knows when the time is right to dry up the blister.
Only when the brand new skin is ready.
Be careful with hot drinks, unluckiest kid.
# He's the unluckiest kid. #
Now, my humerus weighs that and my radius weighs this,
and I subtract the amount my fingernails would weigh,
and I factor in the surface area of my skin and I know the...
What are you doing?
I'm trying to work out how much fat is in my arm.
Xand, you do know there's a much easier way of working
-out your body fat.
It's time for investigation ouch.
This is my fat.
You need fat to keep your body working.
It keeps you warm and whether you're kicking a football or jumping
into a swimming pool, it's fat that stores the energy to help you do it.
But if fat's so amazing, how come we're always being
told we've got too much of it?
There are tests going on here at Warwick University that might
answer that question.
Meet the bod pod.
No, I'm not being sent into space.
With the help of Dr Philip McTernan,
this cool bit of kit is going to measure how much
fat I have on my body.
OK, so what do I do? Just get in it?
No. There's one thing that you need to do first.
You need to make sure that we have something that is much
tighter than this.
Well, luckily, I'm wearing my Operation Ouch leotard.
You might be wondering why I've agreed to wear this,
but the pod needs to take very precise measurements,
so baggy clothing and loose hair are no good.
This device works by measuring the amount of room my body takes
up in this enclosed space.
It feels very claustrophobic.
Luckily I've got a nice big window, so I can see.
And a few fancy computer calculations later,
we have my stats.
There we go.
Percentage fat - 13.8%.
That's very good. It means, you know, you're fit, healthy
and you've got the right amount of fat, that's for sure.
So if I'm 13.8% body fat, how much fat is there on me?
To give you an idea.
This is standard cooking oil but if you had 12 bottles of this,
this would equate to how much fat you have in your body.
This is a really nice illustration of how amazing
fat is as an energy store.
I have 12 bottles of fat like this in my body
and that's enough energy for me to run 30 marathons.
And it also explains why fat is
so hard to get rid of, because you've got to do a huge
amount of work to get rid of a relatively small amount of fat.
So, more exercise will get rid of it, but to understand why
too much fat can be bad we need to get a closer look.
I'm about to get a fat biopsy,
and that's when some fat is taken out of my tummy using a huge needle.
Now, obviously Xand and I aren't afraid of big needles,
but if you're squeamish, you need to turn off the television,
leave the room and go and hide under your bed.
Done that? Good.
Dr Millan, show us the needle.
I told you it was big.
Xand? Where's Xand? Xand said he'd do this.
I've had a local anaesthetic, so I can't feel anything.
And the doctor's cut a little hole in my tummy so that he can get that
huge needle in and some of my fat out.
Oh, wow, yeah.
So, this yellow stuff floating on the top here,
this is the fat from my tummy.
And the average person has 50 billion fat cells,
more fat cells than there are people on the planet.
Now it may look like we've used a huge needle
and not got very much fat, but we don't need that much cos
we're going to have a look at some fat up close, under the microscope.
So, let's see what the cells actually look like.
These are my fat cells and these belong to a person who has a
higher fat content in their body.
Why are their cells looking different to mine?
We can see from here, you have a lot smaller fat cells.
Now someone who has more weight, they have bigger fat cells.
So, a person with more fat doesn't necessarily have more cells -
they've just got more fat in each cell.
Yes. So, eventually, the fat spills over and then what happens is
that you can get fat in your liver, you can get it in your heart,
which affects how they function and how your body functions as a whole.
So, although body fat is vital to life, because it's where the
energy from the food we eat is stored,
it's really important we have the right amount of it.
Too much of it can put you at risk of conditions like heart
disease and cancer, so I for one am going to keep up with my exercise.
I must get Xand one of these leotards.
Our next patient has an unusual habit.
And because of that she's ended up in accident and emergency.
In the emergency department, nine-year-old Brody has arrived
with her mum and eeew!
My finger's got yellow pus in it.
Yes, it has.
It's where I've been biting my fingers...
-You must bite your fingers a lot, Brody.
-Oh, she does!
Brody loves nibbling her nails.
She'll nibble them anywhere.
At home, on the bus,
even in her sleep.
But why, Chris?
Well, maybe her fingers taste of really yummy sausages or
-How about bananas?
-That's ridiculous, Xand.
Fingers can't turn into bananas. Look, let's forget the fingers.
Let's just face it, she loves biting her nails
and now the germs have gone in and they're loving it.
We've tried painting them with nice colour nail varnish,
but that hasn't stopped it. Not good. Not nice.
Why do you do it, Brody?
I don't know.
I just like it.
Here's Dr Shammi Ramlakhan to examined that pussy appendage.
Did you hurt it? Did you knock it or...?
Not exactly, Doc.
I think it's with me biting my nails.
Ah. OK. Can I have a look?
Can you bend?
Good. So, that's what happens when you bite your nails, isn't it?
Brody has a small abscess.
We need to just drain that so that her finger feels better,
and that it doesn't spread and become more serious.
Yep, that pus has got to come out.
What we're going to have to do is put a needle in there,
basically, just to release that. OK?
Now it's time for action.
Don't bite your other hand, Brody.
-Some cold spray just to make sure that...
-It goes like ice.
..just to make sure it's really numb.
Numb or not, Brody's not watching, but it's a very straight
forward jab with a needle and...
We're all done.
-That pus has been released, Xand.
-It certainly has.
What do you think, Brody?
-Can't you put a bandage on it?
-Yeah, a plaster on.
That will be enough to keep any nasties out,
but will all this stop Brody from biting her nails?
Hopefully I'll try and stop biting my nails.
Yes, hopefully. Fingers crossed.
Next time, this man reveals a terrifying secret.
I discover what happens when you lose your senses.
And now I'm seeing things AND hearing things.
And we reveal an amazing trick your body does every time you swallow.
You all right, down there?
-So, that's it till next time.
Subtitles By Red Bee Media Ltd
The doctors take a close-up look at how the eye works, and Dr Chris finds out what body fat does by looking at some of his own under a microscope. Meanwhile, over in accident and emergency, one patient has a mystery rash and another has a bad infection under her fingernail.