0:00:03 > 0:00:07# There are lots of things all around us
0:00:07 > 0:00:10# Exciting things that surround us
0:00:10 > 0:00:13- # But how does it work? - Do you know?
0:00:13 > 0:00:17- # How is it made? - Do you know?
0:00:17 > 0:00:20# Things that go up Things that go down
0:00:20 > 0:00:24# Things that go pop! Things that go around
0:00:24 > 0:00:27# With special cameras to show you inside
0:00:27 > 0:00:30# It's going to be a big surprise
0:00:30 > 0:00:33- # But how does it work? - Do you know?
0:00:33 > 0:00:37- # How is it made? - Do you know?
0:00:37 > 0:00:38# Do you know? #
0:00:38 > 0:00:40Let's find out!
0:00:42 > 0:00:45Hello, I'm Maddie, and today I'm visiting a hospital.
0:00:45 > 0:00:48Have you ever been to a hospital?
0:00:48 > 0:00:50They're very special places
0:00:50 > 0:00:53because inside there are lots of doctors and nurses
0:00:53 > 0:00:57who help people get better if they're poorly or hurt.
0:00:58 > 0:01:02Sometimes doctors use special machines to help people,
0:01:02 > 0:01:06and there's one machine you might've seen before.
0:01:06 > 0:01:08Let's go inside and have a look.
0:01:08 > 0:01:12We're in a consulting room where you see a doctor,
0:01:12 > 0:01:14and this is the machine.
0:01:14 > 0:01:17It's called a blood pressure monitor.
0:01:21 > 0:01:24Your heart pumps blood all around your body -
0:01:24 > 0:01:27to your head, to your fingers and toes -
0:01:27 > 0:01:30and doctors and nurses use blood pressure monitors
0:01:30 > 0:01:34to check that your blood is flowing nicely through your body.
0:01:34 > 0:01:37It's called checking your blood pressure.
0:01:38 > 0:01:43But do you know how a blood pressure monitor works?
0:01:44 > 0:01:46Let's find out.
0:01:46 > 0:01:49How does it work?
0:01:49 > 0:01:52A blood pressure monitor.
0:01:55 > 0:01:58This is Amanda and she's going to check my blood pressure.
0:01:58 > 0:02:03Blood pressure shows how easily blood passes through blood vessels,
0:02:03 > 0:02:07and to measure it, she's going to use the blood pressure monitor.
0:02:13 > 0:02:17The first thing that Amanda is doing, she's putting this bit -
0:02:17 > 0:02:20it's called the cuff - around the top of my arm.
0:02:23 > 0:02:26Now Amanda is pressing a button
0:02:26 > 0:02:28which makes air travel from the machine
0:02:28 > 0:02:31through this tube and into the cuff.
0:02:31 > 0:02:32The cuff is blowing up.
0:02:32 > 0:02:37It's like blowing up armbands when you go to the swimming pool.
0:02:37 > 0:02:40BUZZING
0:02:44 > 0:02:46Did you hear that sound?
0:02:46 > 0:02:51That buzzing sound was the machine working and inflating the cuff.
0:02:51 > 0:02:54BUZZING I can feel the cuff
0:02:54 > 0:02:56getting tighter and tighter.
0:02:56 > 0:03:01It's a bit like having your arm squeezed, but it doesn't hurt.
0:03:01 > 0:03:03When it's ready, we'll hear a little beep
0:03:03 > 0:03:08and that will tell Amanda it's ready so she can check my blood pressure.
0:03:08 > 0:03:11BEEPING And that was the beeping sound.
0:03:11 > 0:03:15If you look at the monitor, you can see two numbers,
0:03:15 > 0:03:18and those numbers will tell Amanda if my blood pressure is OK.
0:03:18 > 0:03:24- Amanda, how's my blood pressure? - It's fine today, Maddie.- Thank you.
0:03:24 > 0:03:26So, my blood pressure is nice and healthy.
0:03:26 > 0:03:31But how does the cuff tightening around my arm tell the machine
0:03:31 > 0:03:34and Amanda that my blood pressure is OK?
0:03:34 > 0:03:38To find out, we need to see what's going on inside my body
0:03:38 > 0:03:40when my blood pressure is being taken.
0:03:42 > 0:03:45Your heart pumps blood all around your body.
0:03:45 > 0:03:47With each heartbeat, it pumps blood
0:03:47 > 0:03:51through lots of little tubes called blood vessels.
0:03:51 > 0:03:53Having good blood pressure
0:03:53 > 0:03:57means your blood is flowing nice and easily around your body.
0:03:57 > 0:04:00It's not going too fast or too slow.
0:04:00 > 0:04:02When your blood pressure is checked,
0:04:02 > 0:04:05the cuff on the monitor fills with air
0:04:05 > 0:04:07and it gets bigger and bigger.
0:04:07 > 0:04:10The bigger it grows, the tighter it gets.
0:04:10 > 0:04:12This squeezes the blood vessels
0:04:12 > 0:04:16so the machine can measure how easily blood travels through.
0:04:16 > 0:04:20The doctor can tell your blood pressure by the numbers shown.
0:04:20 > 0:04:23If you've ever had your blood pressure taken,
0:04:23 > 0:04:26then you know it feels funny as it tightens on your arm,
0:04:26 > 0:04:27but it doesn't hurt.
0:04:27 > 0:04:32But do you know what blood vessels look like?
0:04:32 > 0:04:36Well, I don't have a special camera with me today.
0:04:36 > 0:04:39Instead I have a very special light,
0:04:39 > 0:04:44and it shows you what's happening under your skin.
0:04:44 > 0:04:48But first we need to dim the lights and turn it on.
0:04:48 > 0:04:51BEEPING
0:04:52 > 0:04:54Wow! That's amazing!
0:04:54 > 0:04:59It looks like there are lots of branches of trees inside my arms,
0:04:59 > 0:05:02or the veins that you see on a leaf,
0:05:02 > 0:05:06but what you're actually seeing are my blood vessels.
0:05:06 > 0:05:11This special light uses a laser to show you your blood vessels
0:05:11 > 0:05:16under your skin, and there are so many in my arm.
0:05:16 > 0:05:20Look at my hand. My hand is full of blood vessels.
0:05:21 > 0:05:26I can follow these blood vessels and veins from my hand
0:05:26 > 0:05:31all the way up my arm, even to my elbow.
0:05:31 > 0:05:33Can you see those dark patches?
0:05:33 > 0:05:37That's the blood flowing freely around my body.
0:05:37 > 0:05:39That is incredible.
0:05:39 > 0:05:45How amazing to be able to see under your skin using a special light.
0:05:51 > 0:05:55I loved being able to see under my skin
0:05:55 > 0:05:58and learning how a blood pressure monitor works.
0:05:58 > 0:06:01What was your favourite bit?
0:06:01 > 0:06:03Do you remember what you call
0:06:03 > 0:06:07the part of the blood pressure monitor which goes around your arm?
0:06:08 > 0:06:12That's right. It's called the cuff.
0:06:12 > 0:06:16Did you hear this sound when the cuff was blowing up
0:06:16 > 0:06:18with air like a balloon?
0:06:18 > 0:06:20BUZZING
0:06:28 > 0:06:30And did you see the blood vessels in my arm
0:06:30 > 0:06:33when I used my special light?
0:06:33 > 0:06:35Wow. That's amazing!
0:06:35 > 0:06:40It looks like there are lots of branches of trees inside my arms,
0:06:40 > 0:06:42or the veins that you see on a leaf.
0:06:49 > 0:06:52If you ever need to have your blood pressure checked
0:06:52 > 0:06:56or see someone else checked, you'll know how the monitor works,
0:06:56 > 0:07:00and what your veins look like inside your body.
0:07:00 > 0:07:04There are lots of reasons why people might come to a hospital,
0:07:04 > 0:07:07and one of them is if they break a bone.
0:07:07 > 0:07:09I broke my arm when I was younger.
0:07:09 > 0:07:13Have you ever broken an arm? Or a leg? Or a finger?
0:07:13 > 0:07:14Whatever you break,
0:07:14 > 0:07:17there are special doctors and nurses in hospitals
0:07:17 > 0:07:19who help fix broken bones,
0:07:19 > 0:07:22and there's something they use to put on a broken bone
0:07:22 > 0:07:24to help fix it.
0:07:24 > 0:07:26Can you guess what it is?
0:07:27 > 0:07:30That's right. It's a cast.
0:07:30 > 0:07:36This is a cast for an arm, but do you know how it's made?
0:07:36 > 0:07:38Let's find out.
0:07:38 > 0:07:41How is it made?
0:07:41 > 0:07:42A cast.
0:07:42 > 0:07:44When a bone is broken,
0:07:44 > 0:07:48a special photograph is taken called an X-ray
0:07:48 > 0:07:52and it shows the doctor what the bone looks like inside a body.
0:07:52 > 0:07:55An X-ray looks like this.
0:07:55 > 0:07:57This is an X-ray of an arm.
0:07:57 > 0:08:01And can you see that the bone here is broken?
0:08:01 > 0:08:05To fix it, the bone needs to be held still for a few weeks
0:08:05 > 0:08:07so it can be made straight again.
0:08:07 > 0:08:10And here after it's been put in a cast,
0:08:10 > 0:08:14you can see that the bone is now straight and it's healed.
0:08:14 > 0:08:18But I want to see how a cast is made, so I've come here.
0:08:18 > 0:08:22This is the plaster room where plaster is put on broken bones
0:08:22 > 0:08:24to help them get better.
0:08:24 > 0:08:27You can get different types of cast -
0:08:27 > 0:08:29a plaster cast, which is made from bandages
0:08:29 > 0:08:32covered in a special type of clay,
0:08:32 > 0:08:35or fibreglass, which is a special bandage
0:08:35 > 0:08:37made from woven glass strands.
0:08:37 > 0:08:39This is Sean and he's going
0:08:39 > 0:08:42to be putting a fibreglass cast on my arm.
0:08:42 > 0:08:47Now, I haven't broken my arm, but we've been given special permission
0:08:47 > 0:08:51for Sean to put a cast on me so we can show you how it's made.
0:08:53 > 0:08:57First, Sean is putting a nice, soft layer around my arm,
0:08:57 > 0:09:01and it looks like a big long sock.
0:09:01 > 0:09:04There's even a little sock for my thumb.
0:09:07 > 0:09:10Next, Sean is wrapping my arm in padding.
0:09:10 > 0:09:13This will make the bandage really comfortable.
0:09:19 > 0:09:21It's lovely and soft.
0:09:23 > 0:09:25Now it's time for the bandage,
0:09:25 > 0:09:28and there are lots of colours to choose from.
0:09:28 > 0:09:30I've gone with blue.
0:09:33 > 0:09:37First, Sean has dipped the bandage in water,
0:09:37 > 0:09:39and that's made it easy to work with.
0:09:39 > 0:09:42And it's sticky, so it sticks to itself
0:09:42 > 0:09:46as it's being wrapped around my arm.
0:09:46 > 0:09:49It does feel really warm.
0:09:49 > 0:09:54It's a lovely, cosy, snugly feeling.
0:09:54 > 0:09:57And the bandage sets really quickly.
0:09:57 > 0:10:01That means it goes hard, and that's what will protect my bone
0:10:01 > 0:10:02and help it to get better.
0:10:06 > 0:10:11Oh, that's such a strange feeling.
0:10:11 > 0:10:14Sean smoothes the cast out and then he's finished.
0:10:14 > 0:10:19My arm feels really protected and safe.
0:10:19 > 0:10:21I love the colour too.
0:10:21 > 0:10:25You could have all sorts of colours - red, green.
0:10:25 > 0:10:28How about pink? What's your favourite colour?
0:10:28 > 0:10:32I think I'll stick with blue.
0:10:32 > 0:10:34Now the bandage is on my arm,
0:10:34 > 0:10:37we need to wait for it to dry and set so it goes hard.
0:10:37 > 0:10:41Let's use my special camera to take a closer look.
0:10:42 > 0:10:45This is a microscope,
0:10:45 > 0:10:48and it lets us see really small things in close detail.
0:10:52 > 0:10:54Wow.
0:10:54 > 0:10:57Look at the bandage.
0:10:57 > 0:11:00Can you see all the fibreglass strands
0:11:00 > 0:11:03looping through the material of the bandage?
0:11:03 > 0:11:09That is amazing. It looks like blue rope covered in glue, doesn't it?
0:11:11 > 0:11:13What do you think it looks like?
0:11:16 > 0:11:18This is going to set.
0:11:18 > 0:11:21It'll become really hard and this will protect my arm.
0:11:21 > 0:11:26That is brilliant. Time to see if my cast is set.
0:11:26 > 0:11:28Listen to the sound when I tap it.
0:11:28 > 0:11:31KNOCKING It sounds like knocking on a door.
0:11:31 > 0:11:35KNOCKING Now the cast is dry and hard,
0:11:35 > 0:11:37so if there was a broken bone inside here,
0:11:37 > 0:11:42my arm would be kept still and safe so it could heal and get better.
0:11:42 > 0:11:46But now it's dry, there's something really fun we can do to it.
0:11:46 > 0:11:49We can draw on it with sparkles.
0:11:55 > 0:11:58There we go. A sparkly heart.
0:11:58 > 0:12:01You could have all sorts of pictures on a cast.
0:12:01 > 0:12:03What picture would you like to draw?
0:12:03 > 0:12:06Now, usually, it takes a couple of weeks
0:12:06 > 0:12:09for a broken bone to get better, but luckily,
0:12:09 > 0:12:11I don't have a broken arm,
0:12:11 > 0:12:14so Sean is going to take the cast off for me.
0:12:20 > 0:12:23Well, my cast is off and my arm is back to normal.
0:12:23 > 0:12:27What was your favourite bit about seeing how a cast was made?
0:12:28 > 0:12:31Do you remember what colour my cast was?
0:12:31 > 0:12:33That's right, it was blue,
0:12:33 > 0:12:36but you can get all sorts of colours.
0:12:36 > 0:12:39Which colour would you choose?
0:12:39 > 0:12:41Did you hear the sound the cast made
0:12:41 > 0:12:43when I tapped it? KNOCKING
0:12:43 > 0:12:47It sounded like knocking on a door. KNOCKING
0:12:47 > 0:12:50And did you see what the fibreglass cast looked like
0:12:50 > 0:12:53when I filmed it with my special camera?
0:12:53 > 0:12:57It looks like blue rope covered in glue, doesn't it?
0:12:57 > 0:12:59That is brilliant.
0:13:05 > 0:13:08So, the next time you see someone with a fibreglass cast
0:13:08 > 0:13:12or you have one, you'll know how they're made.
0:13:12 > 0:13:15And now you know how a blood pressure monitor works
0:13:15 > 0:13:18and how it helps doctors and nurses check
0:13:18 > 0:13:20the blood is flowing nicely in your body.
0:13:20 > 0:13:22I'll see you next time.
0:13:25 > 0:13:28# There are lots of things all around us
0:13:28 > 0:13:31# Exciting things that surround us
0:13:31 > 0:13:35- # But how does it work? - Do you know?
0:13:35 > 0:13:38- # How is it made? - Do you know?
0:13:38 > 0:13:40# Do you know? #
0:13:40 > 0:13:42Let's find out!