The Human Body (1998) s01e02 Episode Script

(FAST HEARTBEAT) You're looking at a baby's heart.
It's beating 120 times a minute.
But, amazingly, it's not the only thing keeping this human being alive.
That's done by the most sophisticated life-support machine on Earth.
To find that machine, we have to leave the heart and travel through an artery the thickness of a drinking straw.
(L0UD SW00SHING) Every one of us has an almost identical network of arteries and veins.
Identical, that is, except for this one.
No one watching has a blood vessel like this.
It's a spiralling link between this body and its life-support.
And at its end, a mass of tubes so tiny even blood cells appear huge.
Through a wall comes the sound of the engine room.
(MUFFLED SW00SHING) It's a mother's heart, and we've just made the journey from inside the heart of her unborn baby.
This film is the story of the unique relationship between mother and baby which is at the start of every new life.
(CHURCH BELLS) 0ver a hundred million acts of sexual intercourse take place each day in the world.
These result in around 910,000 conceptions and, nine months later, 400,000 babies.
Many of those babies will be first glimpsed like this, with ultrasound.
But we can see them differently.
Stack a hundred ultrasound pictures together and a new image emerges: a remarkable three-dimensional picture of a child yet to be born.
Today, new technology is letting us see the world of the unborn in a completely new way.
It also lets us retrace its past from a baby just before birth to a foetus of thirteen weeks.
And further back, unravelling the dazzling complexity of the embryo at six weeks and four and three .
.
until we're back at the beginning, with the cells that start the whole thing off.
An egg, and a hundred times smaller, a single sperm.
The process looks so elegant you'd think it was simple.
But you'd be wrong.
These are my sperm, amazingly about 500 million of them from a single ejaculation.
With just this one ejaculation it should be possible to impregnate all the fertile women of Western Europe.
And I'm nothing special.
In actual fact, we need all these millions of sperm to have any realistic chance of achieving just one pregnancy.
Why? Because pregnancy is difficult.
It's a struggle to get pregnant, it's a struggle to stay pregnant, it's a struggle to give birth and it's a struggle to be born.
By filming every two weeks, we squeezed the nine months it takes to create a new life into less than a minute.
Having a baby is a common enough experience and we feel we know a lot about it.
But more than half of what's actually going on inside our bodies is a mystery even to doctors.
It's our greatest achievement and yet it's cloaked in secrecy.
And even when we live through it, experiencing the months of pregnancy first hand, our bodies still conceal the marvel that's going on within.
In this film I want to look at that time afresh, over a single day and over 300 days.
We'll follow the complexities and difficulties of the beginning of life.
We'll condense a year into just a few minutes and reveal how, moment by moment, month by month, a struggle to be born unfolds.
And we'll show how, time after time, the human body has to overcome the most daunting of obstacles to complete the everyday miracle of new life.
I think we talked fairly quickly about having children.
I think we decided fairly quickly not to have them straight away.
Yeah, but it was never an issue as to whether we would or wouldn't, I think.
We just both assumed we would.
It was something that didn't have to be discussed as a possibility or a definite no-no.
It was more a question of when.
Phillippa and Jeff Watson live in Bath.
They're both in their thirties.
Five months ago, they started trying for a baby.
(JEFF) I assumed very much that as soon as Phillippa came off the Pill that getting pregnant would be a piece of cake, but I'm not sure that's the case.
Well, I definitely thought, because all my previous experience has been about contraception and how important it is, I thought it would be very easy to get pregnant.
There would be no problem at all, but, in fact, that's not the case.
The more you read, the more you talk to other people, you discover that it's actually not that easy.
And, er, my opinion at the moment is that I wonder how people actually do get pregnant.
Seems very, very difficult.
And Phillippa is right, it is difficult.
There are only about 30 days a year when a woman has a chance of becoming pregnant.
And even on one of those days a whole chain of unrelated events needs to click into place.
Success depends on a cycle that's been part of a woman's life since puberty.
With a new medical imaging technique developed especially for this series, we can see inside Phillippa.
Nestling deep in her pelvis lies Phillippa's uterus - her womb.
It's a mass of muscle in which a baby could one day grow.
From the top of the uterus on either side comes a Fallopian tube, reaching out towards one of her ovaries, here coloured white.
This is where her lifetime store of eggs is waiting.
They were all formed when Phillippa was just an eight-week-old embryo.
At puberty something remarkable happened.
Inside Phillippa's brain a tiny gland, her pituitary, signalled to her ovaries to start to release some of those eggs.
Since then, month after month, that's what's happened.
And though it's never been shown on television before, you're about to see what ovulation looks like.
We're inside one of the Fallopian tubes, heading towards the ovary.
And at the end of the tube, there it is.
That huge white moon is her ovary.
Inside it is an egg about to be released.
Suddenly, the surface of the ovary breaks, revealing a red wound.
It looks enormous, but it's actually only a couple of millimetres across.
The end of the Fallopian tube rubs against it in time with the woman's pulse.
Then, at the bottom of the wound, a tiny hole appears.
And hidden within is the egg.
A strand of sticky, almost see-through cells is pulled away by the rubbing Fallopian tubes.
They're nurse cells, up to five million of them, ready to feed and nurture the egg.
The egg itself is deep within them.
This is ovulation.
It will happen just 400 times in a woman's life.
It is the beginning of the possibility of new life.
As the egg is pulled from the ovary into the Fallopian tube, the race to pregnancy has begun.
Inside the folds of the Fallopian tube, the egg and its sticky entourage are squeezed along.
But time is already running out.
The egg has perhaps just 24 hours to be fertilized.
After that it'll die.
And to be fertilized it needs to meet a vital ingredient: sperm.
I'm sometimes asked what's the best way to make sure a sperm meets an egg in those vital 24 hours.
The answer's rather technical: have sex and have it often.
As our bodies come nearer and nearer to orgasm, every part gears up in anticipation.
(DULL RUMBLING) Sperm have to travel through the tangle of tubing in the testicle to the end of the erect penis.
It's a distance of nearly a metre.
The white fluid they're in is mainly nutrients for their long journey ahead.
At orgasm, huge muscular contractions propel the fluid on its final ride through the man's body and into the woman's.
(L0UD SW00SHING) And now, inside the vagina, sperm face the first of many mortal dangers.
The walls of a woman's vagina are coated in acid to protect her from infection by bacteria.
But it's lethal to sperm.
Within minutes, the walls are littered with the corpses of millions.
And within an hour most of the 500 million sperm that set off are dead.
Yet the woman's body can help, as well as hinder the sperm's progress.
It's possible the contractions of her orgasm help to draw sperm into her uterus.
0r even that the junction between the vagina and the uterus, her cervix, is dipped time and time again into a pool of waiting sperm.
It's also likely that in the hours after sex the uterus itself contracts, helping to carry the sperm on their way.
Even so, the sperm have been all but annihilated.
0nly a few thousand will complete the journey across her uterus and into her Fallopian tubes.
Then, minutes, hours or even days after they started out, the sperm that have struggled so far will find what they set out for.
Deep in the folds of the Fallopian tube, here magnified a thousand times - an egg.
As they get near, the sperm are lured towards their goal by a chemical signal sent out from the egg.
Each sperm carries in its head all the genetic information the man will contribute, and this now needs to meet with the mother's genetic information waiting inside the egg.
Suddenly one of the sperm, which has been burrowing into the wall of the egg, breaks right through.
Inside the egg, the genetic information is gathered in two tiny balls.
Details from Phillippa are in one and from Jeff in the other.
In a moment the information will fuse together.
And the instant that happens the unique inherited characteristics of a new life will be fixed.
All the information from Phillippa and Jeff is now there to determine whether their baby will be a boy or a girl, tall or short, have blue eyes or brown.
Even whether it's predisposed to heart disease or certain kinds of cancer.
But, as yet, the baby itself does not exist.
In fact, the chances of the fertilized egg surviving are far from certain.
Some will do nothing.
But just over half will do this.
It makes a copy of itself and divides, again and again.
Seen down the lens of a laser microscope, the dividing egg looks like a strange berry.
It's a cluster of eight identical cells.
But they won't be identical for long.
As Phillippa and Jeff continue life as usual, they're completely unaware of the changes going on inside Phillippa's body.
Hour after hour, the fertilized egg continues to change, and all the time it's journeying along her Fallopian tube towards her uterus.
Her uterus, too, is transforming.
Its lining has swollen and thickened.
We're seeing a part of the lining magnified almost ten thousand times.
It's the landing ground for the fertilized egg.
But the egg establishes itself in the womb in a very unexpected manner that will set the tone for the next nine months.
This is Hirudo medicinalis, better known to you and me as a leech.
It's a parasite.
It takes whatever it needs to live by sucking the blood of whatever it can latch on to.
In this case, that's me.
As it sucks my blood, it takes from it all that it needs to live.
It literally lives off me.
And the whole of pregnancy is shaped by a similar kind of parasitic relationship.
Unlike the leech, the developing embryo doesn't suck the mother's blood.
But it does raid her blood for the raw materials it needs to grow.
From the word go, both leech and embryo are out for themselves.
The cells of the embryo spread out as they divide and invade the mother's uterus.
It's almost an aggressive attack.
But, surprisingly, the army of foreign cells does not meet any resistance from the mother's own defence systems.
If anything else grew inside her at the same tireless rate, it would either be killed or eventually it would kill her.
Quite how the embryo pulls off this life-saving trick remains a mystery.
It's around now that a woman may for the first time sense there's something going on in her body.
I tend to get up in the middle of the night to go to the bathroom anyway.
And I woke up and I suddenly had this urge to try out the pregnancy test kit.
So I was rattling around in the dark, opening drawers and bashing away, and I'm not quite sure what Jeff thought was going on.
Then I disappeared into the bathroom for ten minutes and, I mean, this was all at four o'clock in the morning and I crawled back into bed, sort of said, And we did wander around for a couple of days after that, grinning at each other like Cheshire cats.
But the struggle of pregnancy is by no means over.
It's really only just starting.
This is what's growing inside Phillippa's womb just three weeks after fertilization.
The round ball is the yolk sac, a temporary food store.
Stretched across the top is the embryo itself.
Within it, thousands of new cells are created every second.
And somehow they are given instructions to where they fit in.
This long column is the foundation of the nervous system and the brain.
The basic layout of the body is from a very early stage quite familiar.
At six weeks, the developing spine is bent double.
A bud of an arm is beginning to form near the top.
This is the head.
But the exact details of each embryo are unique.
It's being built to a genetic blueprint which is a one-off, never tried before.
Work starts at the head and progresses down.
By six and a half weeks, that makes the head, on the left, disproportionately large.
All four limbs have sprouted, though the right arm is hidden behind the umbilical cord.
But as the embryo's genetic blueprint is brand-new, it's never actually been tested.
Each new step could reveal a fatal mistake.
And they're much more common than you might think.
It's a harsh reality, but what you see here will not inevitably become a baby.
Five out of six embryos will not have survived up to eight weeks in the womb.
It's almost impossible to see a developing feature and not imagine it finished.
But the truth is this will only become an eye if luck stays on its side.
Every moment we watch, this embryo is taking another step into uncharted territory.
The embryo has reached eight weeks.
It looks like it may become a boy.
But, in fact, what you're looking at could develop not into a penis, but a clitoris.
The embryo's sex is hidden.
For now, both male and female look the same.
Also hidden is the construction work inside the body.
Millions of cells are becoming bone, lungs and brain.
At this stage, nine weeks, the stomach is producing its own digestive juices, and the heart has started its vigorous pumping.
We now call it not an embryo, but a foetus.
But the name-change doesn't mean its future is any more assured.
The risk of failure still accompanies each new development.
Footprints and palmprints are engraved.
All the time, the work is fuelled by the supply line, the umbilical cord, linking the foetus to the mother.
Now a crucial stage of pregnancy is over.
The foetus has managed to complete the basic structures of its body.
It has taken twelve weeks.
The rest of pregnancy will be chiefly devoted to getting bigger.
And it must get a very great deal bigger, because the scale of these pictures is deceptive.
All that we've seen so far is in a foetus no bigger than this.
This is a model of a twelve-week foetus and it's tiny.
It weighs about 14 grammes.
That's roughly the weight of a one-pound coin.
What's so remarkable is that something this small can cause such an upheaval in its mother's body.
My breasts got a lot bigger very quickly and that was the first thing I noticed, which I wasn't prepared for.
Because, obviously, you look at all the pictures of the week-by-week guide and it's always the tummy growing bigger, and they really don't concentrate on that part of the anatomy at all.
So I got a bit, not worried, but a bit sort of surprised that it was so immediate, because you know that they would get large, but I didn't think it would be at the beginning.
With a camera that shows up heat as colour, you can see that process happening.
Hot areas of Phillippa show up as yellow or red.
Before she was pregnant, her breasts were actually colder than most of the rest of her body.
In the first three months of pregnancy, a surge of hormones causes the blood vessels around the breasts to expand.
Extra blood flow in these hot, red areas feeds the breast tissue as it gears up to provide milk.
The breast is made up of a mass of tiny glands.
It's these that mature and swell.
A maze of passages connects the glands to milk reservoirs behind the nipples.
From very early on, the glands can begin to produce milk, filling the tubes and making the breasts very sore.
That's why painful breasts are often a problem in early pregnancy.
(SEAGULLS CRY) But by far the most common complaint is feeling sick.
This is truly miserable.
It's maybe the closest I can get to what three quarters of all women feel during early pregnancy: morning sickness.
It's rather unpleasantly like being seasick.
First you're worried you're gonna die, then you're worried you're not.
Early in pregnancy the mother's body seems to become much more sensitive to the waves of chemicals flowing through it.
Many mildly toxic things, which we normally eat and drink quite happily, can throw the pregnant body into fits of nausea.
But the good news is that most women feel better by about twelve weeks.
Although you're not exactly home and dry, after that things are much more stable for both mother and foetus.
So, if the world of the mother can be horribly uncomfortable, what about the world of the foetus? In the past, we thought of it as a calm, relaxing place.
But how realistic is that? If you or I were in the womb, what would it be like? You'd be in the middle of someone else's body.
Their heart, which is bigger than you, would be thundering away.
Around you would be metres and metres of arteries and veins, filled with someone else's blood.
(W0MAN C0UGHING) And how would you get any peace, when above you, two cavernous lungs work day and night? (L0UD BL0WING) And worse still, right next to you would be the biggest distraction of all.
(WOMAN) Excuse me.
Three meals a day and who knows how many ice cream and gherkin sandwiches have to go somewhere.
And to top it all, you'd be growing all the time.
The real world inside the womb is dynamic and bustling.
And in the last twenty years the tool that's done most to show us that is ultrasound.
Developed to help doctors screen for potential problems, it allows parents-to-be to see what their baby is up to.
Instead of lying quietly, it's having a go at a kick or even a somersault.
It gulps and swallows up to half a cup of amniotic fluid every day.
From quite early on, it sucks its thumb, a habit which may take years to break.
As it gets bigger, we can see what little room it actually has.
Ultrasound is so sensitive that it will even, if you watch carefully, capture a blink.
There.
Phillippa is now nineteen weeks pregnant and going for her scan.
(SCAN 0PERAT0R) OK, let's show your baby before I do anything else.
So, you can see this is his head, body, heart beating away there in the middle of the chest.
(PHILLIPPA) The legs curled (JEFF) All right, now I can see which way round it is.
(SCAN 0PERAT0R) There you go.
There's a hand.
See the fingers there? (JEFF) Piano player's hands.
(SCAN 0PERAT0R) Baby's just having a yawn.
(PHILLIPPA) Told you it would always be tired like me! (SCAN 0PERAT0R) Plenty of time to rest while it's in here.
It's really the first time it's really brought home to me that you're actually pregnant.
It's absolutely amazing that suddenly I've got to realise that, yes, there is actually something in there.
It was just so moving as well, I was I mean, it was very, very emotional, I I did shed a quiet tear when nobody was looking, but I could've cried a lot more.
And obviously, I mean, afterwards, when they explain what they've checked, it's a great relief to know that everything is all right.
It's gonna be incredible to show this to my mum.
I can't wait to show her, because the technology is incredible, she never had an opportunity to see this.
But here we've got pictures of our future child.
So this is what we know of the foetus' world.
But what, if anything, does it know? By mid-pregnancy, the foetus will have started to develop all five senses, but they're still totally blurred.
Instead of having separate senses, we think a foetus' senses are much less distinct.
Sounds, for instance, may be felt through the skin, as well as heard by the ears.
Likewise, changes in the fluid that surrounds the foetus will be as much smelled as tasted.
Sounds from the outside world will be filtered through the mother's body.
My voice would sound totally different.
(MUFFLED AND DIST0RTED) Perhaps something like this.
(MUFFLED) My own mother wouldn't know it was me.
Whatever sounds can penetrate into the womb, what does a baby actually perceive? That's a hard question to answer, because when we hear or see or feel, we don't just do it with our ears, eyes or hands, but with our fully-developed brain.
0ur ears and eyes, mouth and nose are just sensors.
It's here, deep inside our brain, that we translate the signals they give.
It's our brain that makes sense of our senses.
And in the foetus the brain is still developing.
So, concepts like hearing, seeing or feeling are meaningless.
The brain doesn't just switch on one day.
Rather, it comes on like a dimmer switch, going gradually over many, many months from nothing to being fully on.
I think the next time I go to the midwife I'll have to ask about which position the baby is in.
- Which way round it is? - Well, yeah.
I can't work out whether it's a bottom or what it is that keeps poking out.
- The thing I was feeling earlier on? - Yeah.
Phillippa is now five months pregnant.
Like most women just past the halfway stage, she's blooming.
And that's rather surprising, because inside the baby is starting to dominate.
It's competing with her for the same limited resources, yet they co-exist quite comfortably.
Sometimes the movements are very separate.
And other times it's little, little kicks.
Actually, I might have a little rest now.
The broker of this remarkable peace is perhaps the most amazing organ in Phillippa's body.
It's the placenta.
This is some of the most sophisticated life-support machinery available to doctors anywhere in the world.
Yet this room full of technology cannot begin to compare with the capabilities of this.
For this is a placenta.
It's a kidney dialysis unit, a heart-lung machine, an artificial liver all rolled into one.
It's the go-between.
It's what allows mother and foetus to live together, and for me, it's the most fantastic thing about pregnancy.
Yet all of us, even doctors, tend to take it completely for granted.
Wonderful though it is, I can see why not everyone might share my enthusiasm for it.
But I think it's the great unsung hero of all our lives.
So far in Phillippa's pregnancy, it's been the foetus which has faced the biggest threat.
But, in the final three months, her own body will be pushed to its limits.
Her uterus will increase massively, up to twenty times its normal size.
Her blood supply will increase by more than a third.
And there's a whole lot more weight to go on.
And all the time, the message Phillippa hears from her body is just, ''Carry on as normal.
'' Eventually, the reality of what's going on inside her must start to take its toll.
And what is going on is quite extraordinary.
We're taking a unique view inside Phillippa's body, now that she's seven months pregnant.
Look how big her uterus has grown to house the baby.
It takes up a huge space inside her.
And see how her spine has curved with all the extra weight.
No wonder she gets backache.
Her organs have all been squashed upwards as her uterus has expanded, her stomach, her liver, her lungs.
That's why she feels breathless.
Her large intestine, her colon, is now up near her ribcage.
It used to be much lower.
But the most dramatic change is to Phillippa's heart.
It has to work much harder and to do that it gets bigger.
As it does, it's pushed out of its usual position and it's tilted over to one side.
Hello, baby, how are you today? You've been quite quiet.
Not been a busy day.
Oops, that was a little movement.
Which bit was that, then? What are you doing? Where are you trying to get to? Eh? You're soon gonna run out of space, you won't be able to do that.
I'm not sure your daddy likes watching this.
I think he thinks it's a bit funny.
And probably worries that it hurts, but actually it's quite comforting.
Phillippa and Jeff's baby is due in just six weeks time.
All men must go through the same thing, because you feel fairly helpless.
While all the changes are going on to Phillippa, physically, mentally, emotionally, the same sort of thing is happening to me, but I'm only looking very much from the outside.
There are times that I wish that I could feel the physical side of things, so that I could understand it a little more.
It can be quite difficult when there's not an awful lot you can do, other than carry the shopping or something.
It seems fairly menial by comparison with what's going on to the mother.
I just marvel at the fact that all of this is going on with no real intervention from me.
It's just my body taking over and doing it all.
I'm not in control of it at all, really.
It just all happens.
The birth itself is the most difficult yet of the tasks the body has had to tackle.
So, why has it been so tough to get this far? The easy answer is that our bodies are riddled with imperfections, right from the start.
Sperm so weak they're all but annihilated.
Eggs so fragile they only live for a day.
But the bigger question is, why are we like that? Why are our bodies designed to make each stage of pregnancy so difficult and so dangerous? And of course that's the whole point, our bodies aren't designed at all.
Instead we have evolved.
0ur imperfections are simply problems inherited from our ancestors.
The great triumph, though, is that we have also inherited solutions.
So although the human body makes pregnancy the most complicated task it ever faces, at the same time it makes it look so very easy.
Glimpsed inside the womb with three-dimensional ultrasound, this is a baby about to be born.
It looks fully formed, but in one crucial way it's not yet ready for the world.
Its brain is still nowhere near fully developed.
If it were to wait until it was, it could be in the womb an extra twelve months.
But there's a very simple reason why it can't stay there that long.
To get out, the baby has to travel through the middle of the pelvis.
Any longer in the womb and its head would be too big to fit through.
0ur pelvises have evolved to reach their widest limit.
Any wider and walking would be impossible.
We would have to crawl on all fours.
So if the baby is to come into the world at all, it must do it now, whether its brain is ready or not.
And it's a tight squeeze.
Ten days before it's due, Phillippa's baby is beginning to make its way into the world.
Most unusually for a first-time mother, Phillippa has decided on a home birth.
(MIDWIFE) I'm listening all the way through this one and then afterwards as well.
The muscles that have held the baby enclosed for months now have to be stretched apart to let it out.
With the heat-sensitive camera, you can see the waves of hot muscle action sweeping across Phillippa's tummy during a contraction.
Hour after hour, the walls of the uterus press in upon the baby in powerful, regular contractions.
(MIDWIFE) Now Phillippa's contracting about one every three or four minutes, and they seem to be fairly strong.
I think she's coping really well with the contractions, although she doesn't always think she is.
I think she is doing extremely well.
And we're just hoping that the contractions are making the cervix dilate.
At first the contractions aren't moving the baby.
They are painfully forcing open the neck of Phillippa's womb, her cervix.
It will have to go from closed to ten centimetres wide open.
For a first-time mother, this takes an average of ten hours.
0nce the cervix has been opened, the baby's exit route is clear.
The head acts as a battering ram, forging a way for the rest of the body.
To see more clearly what's happening, let's look beneath the skin at the baby preparing for its exit.
It has to perform a difficult manoeuvre.
It's facing us here, but as it enters the pelvis its head gets turned round to face Phillippa's spine, and then its head and neck are bent right back through an angle of ninety degrees.
It's rather like forcing your foot into a Wellington boot.
(PHILLIPPA GR0ANS) (MIDWIFE) Well done.
(MIDWIFE) Well done, the contraction's gone, Phillippa.
(PHILLIPPA) I can't (MIDWIFE) OK.
If you sit Phillippa, if you sit on the edge of the bed.
- And then just put your fingers down.
- I don't think I can.
Just lean back like that, just as you are.
Just reach down and touch the baby's head.
Just inside now, when you're pushing, it comes out quite a lot.
- Oh, no.
- OK, you don't have to.
Big long push again, Phillippa.
That's excellent.
Well done, that's it, keep it there.
(MIDWIFE) Right, let's have a really good push.
(W0MAN) Put your chin down.
(MIDWIFE) That's it.
(MIDWIFE) Take a breath.
(MIDWIFE) One more push, Phillippa, if you can, it's so close.
(W0MAN) That's it, you're doing it now.
(PHILLIPPA SCREAMS) (MIDWIFE) Pant, pant, pant.
Well done.
(PHILLIPPA PANTING) (MIDWIFE) That's the baby's head.
(PHILLIPPA M0ANS) (W0MAN) That's all right.
(MIDWIFE) Big push.
(JEFF) Come on, come on.
(JEFF) Look, look, look.
(JEFF) Look, look.
(PHILLIPPA PANTS L0UDLY) (BABY CRIES) Oh, well done, wee baby.
Perhaps birth should be viewed not so much as an occasion when things can go wrong, but more as a miracle that things can go right, which they do most of the time.
Phillippa gave birth to a healthy baby girl, just one of almost a million babies that share her birth date, all around the world.