Lesson video

Hi everybody.

It's Miss Simkin here, ready to teach your next science lesson.

I hope that you are having a good day.

Today we are going to learn about the human body and how our understanding of the human body has improved and changed over time.

So our lesson question today is this, how has our understanding of the human body changed over time? And this is what we're going to learn about today.

We going to start with our star words.

Then we're going to look at timeline for kind of major developments in human anatomy.

Then we're going to look at blood and surgery.

Don't worry if you are a bit squeamish, I'm not going to show you any photos with any kind of detail, so you don't need to worry at all.

And then at the end of lesson, you will have a chance to take your end of lesson quiz and see how much you have remembered.

For this lesson you'll need the following things, a piece of paper, a pencil, a colouring pencil so you can mark your work in a different colour and a ruler.

If you don't have those things, could you pause the video now and go and get them please.

Great, okay.

Let's get started with our star words.

As always I'm going to say them, and then you're going to say them.

Remember it's important to say them out loud so that we can practise saying the words and also it can help it to stick in our memories.

Anatomy, dissection, microscope, blood, surgery.

Great.

So, human anatomy is the study of the structures of the human body and is key to the practise of health and medicine.

Okay.

So when we're talking about anatomy, we're talking about the body, how it's pieced together, all the different parts it.

Dissection is the action of cutting into a body or into a plant so that you can see what's inside of it.

So dissection is a really important way of learning about the human body.

A microscope is a scientific instrument that's used to study very, very, very small objects.

And it magnifies them, it zooms in so you can see them more clearly.

Blood is the red liquid that circulates around our bodies, lets say if you cut yourself and it carries nutrients and oxygen and other gases around our body.

And surgery is a medical treatment that requires opening up the body.

So sometimes you might need surgery for a certain reason.

So that a doctor, a surgeon, will need to open up your body, make an incision and fix something inside of you.

Okay, so that's what surgery is.

It requires opening up your body.

Sounds scary, but it's actually a really good thing.

Now let's get started with our anatomy timeline.

You are pros at timelines now in this unit.

Can you please pause the video and draw this timeline.

I would suggest unless you have very small neat handwriting, turning your page to landscape, and you can see there are one, and you can see there are five intervals.

You're going to need one, two, three, four, five intervals.

Pause the video and set up your timeline for me now please.

Great.

Okay so, as I go through each stage of the timeline, I will then ask you to pause and put it on your timeline.

So you're drawing your timeline as we go.

One of the very first things we're going to start about is this scientist called Galen.

Now, he was a Greek medical scientist.

He lived in the Roman times and he learned a lot about human anatomy by treating Roman gladiators who were injured and also through studying anatomy by dissecting animals.

So he would dissect animals like monkeys and pigs.

He'd opened them up, he'd look inside them and he learned about their anatomy and then could make guesses about human anatomy.

He was very famous in his time.

He treated many Roman emperors and he published lots and lots of books, all about his learning on human anatomy.

And his ideas about human anatomy remained the main ideas that people followed for 1,500 years, at least in Western medicine, okay.

A big part of the world was following his ideas for 1,500 years.

It's pretty impressive.

Can you pause the video and add this to your timeline please.

Great.

Now people followed his ideas that is until 1,500 years later.

Then when Vesalius came along in the 16th century and he studied human anatomy.

Where he studied anatomy through human dissections.

So unsurprisingly the idea of cutting open a human body to see what's inside of it, is one that has always made people feel quite uncomfortable.

And at the time when Galen was studying anatomy, he wasn't allowed to carry out dissections on human bodies.

But, by the 16th century, Vesalius was.

And so he started to study the human body through human dissections.

And he learnt some really, really important things.

So he compared what textbooks and books that were already published said with what he was seeing in his actual dissections.

And he found more than 200 things that were wrong with Galen's original ideas.

And that's not that surprising is that because we know that our bodies aren't exactly the same as the animals that Galen was studying.

So, one example of a mistake that Vesalius found was that Galen thought that the human jaw only, so your jaw, put your hands on your jaw, can you feel it, move it up and down.

Galen thought that the human jaw only had two bones, but Vesalius found that that was incorrect that human jaws have more than two bones.

And at the age of only 28 he published his textbook, his, well, I'm saying it's a book, it was actually seven volumes.

That's like seven big books, with all that he'd learnt.

That's a really big step in the process of human anatomy.

Can you pause the video and add this to your timeline please.

Great, okay.

And about a 100 years later in the 17th century, microscopes were first used to study human anatomy.

So we learnt about microscopes in our star words They let you see really small things.

And the introduction of microscopes opened up a world of cells, which meant that the human body could be studied in much more detail.

So a cell is like the smallest unit of life that everything in your body is made up of.

But until we had microscopes, we didn't even actually know that.

So microscopes allow the body to be studied in much more detail.

Can you pause the video and add that to your timeline please.

Great.

And then in 1895, the X-ray machine was invented.

Have you ever had an X-ray before? So if you've ever broken or fractured a bone, you might've had an X-ray.

An X-ray machine essentially takes a picture of the bones inside your body.

So it meant that the human body could start to be studied without the need to dissect and open into it.

Which is great.

Can you pause the video and add this to your timeline please.

Brilliant.

And then the last thing on our timeline today is this, in 1977, the MRI scanner was invented.

Now you may also have had an MRI scan before.

If you've injured a part of your body, that's a soft part of your body and it's where you go into a big machine that makes a really loud noise and it can take pictures, images of the inside of your body, not just the bones like an X-ray, but the muscles and the tissues.

So again, this meant that the human body could start to be studied in detail without the need for dissections.

Can you pause the video and add this to your timeline please.

Great, good job.

So you can see that in the Roman times, or even before the Roman times our information about the human body was pretty limited.

Think about your body now, you can't see very much of it 'cause you can't see what's going on inside of you.

And it wasn't until Galen started dissecting animals that we could start to guess what our body would look like inside.

Then Vesalius was actually able to dissect humans and see what was inside of us.

Then microscopes let us zoom in and magnify and see in more detail.

And then we developed X-rays and MRI scanners, which meant that we didn't need to dissect bodies anymore to find out what was going on inside.

Okay.

Now we're going to put these events in order.

You don't need to write them down, but I need you to look carefully to the screen.

You might need to come a bit closer because you're going to need to read what's on the screen.

Which one of these came first? I want you to get your finger and point it on.

You can refer back to your timeline that you've written down if you need to, but see if you can do it from memory.

Which one of these came first? Use your finger to point to it, read it out.

This one came first.

Galen studied anatomy through animal dissections.

Good job.

Okay which one came next? Find it with your finger.

Let's check.

This one, good.

Studied, he studied anatomy through human dissections.

Good job, okay get ready.

Which one was number three? Which one came next? Brilliant, microscopes were used to study anatomy.

Okay, we've only got two left, Which one comes next? X-ray or MRI? Good job.

It was the X-ray, which means that the MRI scanner was the last on our list.

Brilliant.

Okay.

So this is of course just some of the amazing achievements and ways that we learnt about human anatomy over the course of our whole history.

But these and other discoveries have led to some great advances in medicine.

So let's zoom in on a couple of different areas.

The first area we're going to zoom in on is blood.

Now we're going to talk about something called bloodletting, which was used a very long time ago.

It was used in the Roman times, but it was still being used by doctors as a method for treating people into the 19th century.

Okay.

So bloodletting is where a doctor would cut a patient and let some of the blood out of their body.

It's what we call bloodletting.

It's like letting the blood out.

Now, we know now that blood plays an essential role in our bodies.

It's really important and losing too much of it is not very good for you, can result in shock.

And if you lose too much blood you can die.

So it's a bit surprising that bloodletting was the most common procedure performed by surgeons and doctors for almost 2000 years.

And we have physician from the Roman time Galen to thank for that.

He was a very enthusiastic advocate of bloodletting and he used it to treat lots and lots of different things.

Even just like having a fever, he would recommend bloodletting.

Luckily, science has moved on from that.

And one of the development that Vesalius's book and his intricate drawings and discoveries about the human body allowed to happen was the invention of tourniquets.

I'm going to say tourniquets.

Great.

So when we had a better understanding of how blood circulated around the body, then we were, surgeons were able to treat wounds in a better way.

And they developed tools and techniques such as the tourniquets which is a strip of cloth that's tied really tightly around an injured arm or leg to stop the bleeding.

Okay.

And this can save lives if people have wounds that are bleeding too much.

So you can see already how ideas about blood had changed.

So from bloodletting where doctors were actually removing blood from patients to try and help them to tourniquet which is very much stopping blood from leaving patients.

And then, more developments to do with blood occurred.

So this is Charles Drew and he was an American surgeon and medical researcher.

And he researched the field of blood transfusions.

Say it with me, blood transfusions.

So a blood transfusion is when you're given blood from somebody else, a donor.

Which is really good, if you've lost too much blood from your body then you need to have blood donated from somebody else.

And he also improved techniques for blood storage and he applied his expert knowledge to opening the first blood banks.

And blood banks are where we store blood.

So if you, and I hope this never happens, if you were to be in an accident and lose a lot of blood, you'd go to hospital and you would be okay because they have a big blood bank there and they'd be able to give you a blood transfusion of somebody else's blood.

Again, we've got Charles Drew to thank for that.

21 million blood transfusions happen in the US every year.

So it's now a really common practise.

So, where did we start on our blood story? We started with bloodletting, and then what started to happen? An invention that began with T, tourniquets.

And now we've got to blood banks.

Now we can even go a step further than blood banks.

And now, we are able to do something called blood analysis.

And we can actually take small samples of people's blood and analyse them.

Look at them really carefully, look at the chemical and the physical properties and it can help to check for diseases and assess how healthy people are.

It's just really, really.

Okay, got some questions for you.

What is a tourniquet? What was Charles Drew famous for? And what can we use blood analysis for? Have a go answering them by yourselves.

Don't worry if you get one wrong because we'll go through the answers.

But if you need to, you can always flick back in the video, was about to say the window and watch that bit again.

Pause the video and have a go from here now please.

Great, lets check our answers.

So, number one.

A tourniquet is a strip of cloth that is tied tightly around an injured arm or leg to stop it bleeding.

Give yourself a tick if you got that right, if you need to correct your answer, no problem, use a different colour and correct, make your correction.

Number two.

Charles Drew is famous for creating the first blood bank.

And number three.

Blood analysis can be used to check for diseases and assess how healthy you are.

If you need some more time to mark your answers pause the video and do that for me now please.

Great, okay.

Let look at surgery now, and we're going to start with another slightly people used to do.

So if you thought bloodletting was bad, get ready.

So, there is something called trephining.

I'm going to say trephining, sometimes it's called trepanning.

its the same thing.

And this is a surgical procedure where a small hole is cut in the back of a person's head.

Sounds like that will make you better, doesn't it? This procedure was practised as early as 3000 BC, but it continued through the middle ages and even into the Renaissance into the 16th century.

The initial purpose is thought to be a way to let evil spirits leave your body.

So when we didn't have a very good understanding of the human body, people used to blame supernatural reasons for why they would get ill, because they didn't understand what else could be causing it.

And so they thought that drilling a hole in the back of your head would let the evil spirits out.

How glad are you that you are alive today? And if you get ill you don't have to have a hole drilled to the back of your head.

On a scale of one to 10, how happy are you? I'd say 10 out of 10.

Okay.

So, that's our starting point in terms of surgery.

Then surgeons in the middle ages, through to the 18th century we would have called probably barber surgeons.

And they would be able to perform minor surgeries like tooth extraction, that's taking your tooth out or bloodletting, which was something they still thought was a good idea and treating wounds so like war wounds or if you'd got an accident.

But they wouldn't have been able to do the same type of surgery that we do today because they didn't have any anaesthetic, that's medicines that reduce pain and they didn't have any antiseptic, that's medicines that would reduce infection.

And so surgery was still pretty dangerous.

Even those minor surgeries like getting a tooth pulled out could be quite dangerous 'cause you're opening yourself up to infection.

Luckily, we live in the modern age and modern surgery is completely different to trephining and barber surgeons.

So surgery used to be so dangerous because there was no anaesthetic or antiseptic.

And also because people didn't know very much about the body.

So when they wouldn't be able to open it up and know what was going on in there.

Nowadays, we have anaesthetic to numb pain.

We have good hygiene practises.

We have antiseptic conditions in hospitals and because of that and because of our increased knowledge of the human body, we're now able, I say we, doctors and surgeons, are now able to do amazing things.

They are able now to transplant organs from different people's body.

So if there was something wrong with something in your body, one of your organs like your heart or your lungs or your liver or your stomach, you'd now be able to have a transplant and get one of those organs from somewhere else.

And the surgeon would be able to do that for you.

We now also have something called keyhole surgery, which is when only really, really, really small incisions are made.

So your whole body doesn't always need to be opened up for surgery.

Can now do really small incisions to fix some things.

So that's what key hole is.

Why do you think it's called keyhole if it's really small decisions, incisions.

Yes, 'cause a key hole is really small, small.

If you don't believe me try looking through a key hole.

It's very small.

Okay.

Some questions for you.

What is trephining? Let me give you a clue.

Why did surgery used to be so dangerous? And what is keyhole surgery? Pause the video and have a go at answering these questions for me now, please.

Fantastic.

Let's check your answers.

So, trephining is a surgical procedure where a hole is drilled in the back of the human skull.

Or you can say the back of a human's head or the head.

Give yourself a tick if you've got it correct.

Then surgery used to be so dangerous and you could have written any of these reasons, because there was no anaesthetic, no antiseptic and hygiene was bad.

You also could have written cause surgeons didn't know very much about the human body.

And number three Keyhole surgery is a type of surgery that uses only small incisions.

Give yourself a tick if you got those correct.

If you need some more time to add to your answers or to edit them, then pause the video and do that for me now.

Great job today.

That's the end of our lesson.

You've worked really hard and I hope you've learned lots about the history of human medicine and I hope you are now very thankful to live in the modern age so that when you go to the doctor you know that they're not going to let your blood out or drill a hole in the back of your heads.

Don't you forget to do your end of lesson quiz just before you go.

Have a fantastic rest of your day everybody.

I hope it's just filled with sunshine and laughter and I will see you back here, hopefully, for another science lesson.

See you.

Bye everybody.