"There is one thing everyone on earth has in common:" "we all live, eat and breathe within the human body." "For two years, we´ve been exploring this unique dwelling place." "We want to show you what I´ve seen." "To come with us, you´ll have to cross the globe, from Australia... through Africa... to America." "You´ll have to journey into space... and into a place as mysterious but much closer to home." "We´ve developed new techniques to help you get there." "New cameras to show you the way." "And we´ll look at familiar things with a fresh eye." "We´ll voyage inside the body on its journey through life." "We´ll travel through dangers... through miracles... and through time." "We´ll see the human body in all its forms." "From our beginning... to all our ends." "Every day, all over the world... doctors and surgeons are exploring the workings of the human body." "But we´re going to shot it to you in a new light." "This is Charlotte." "She was born just a few hours ago." "Like most of us at birth, there´s really nothing to her:" "a bit of fat, a little sugar, a bit of protein," "Actually, she´s 75%% water." "She´s really just a collection of chemicals." "And yet, she´s the most complicated thing on earth... and during her lifetime... she´ll achieve the most amazing things." "She´ll eat for nearly 3 years... consuming 7,300 eggs... and 160 kg of chocolate." "She´ll produce 40,000 litres of urine... and spend over six months on the loo." "She´ll dribble 1 45 litres of saliva before her first birthday." "She´ll crawl 150 km before she´s two." "From then on, she´ll learn a new word... every two hours for the next ten years." "By the time she´s ten, her heart will have beaten 368,000,000 times." "She´ll spend a little over 12 years watching TV." "And 2 years on the telephone." "She´ll spend two weeks kissing." "She´ll grow 28 metres of fingernail... and 950 km of hair on her head... and more than 2 metres up her nose." "By the age of 21 , she´ll have breathed over 3,500,00 balloons of air." "She´ll work for a total of just over eight years." "And she´ll produce 200 billion new red blood cells each and every day." "She´ll be able to put a name to 2,000 people." "150 of them she´ll call her friends." "She´ll shed 19 kg of dead skin." "She´ll have sex 2,580 times... with five different people." "She´ll fall in love twice." "She´ll blink 415 million times... and her eyes will be able to distinguish over a million colours." "If she gets married, she´ll spend 6,809 pounds on her wedding day." "And there´s a 60%% chance... she´ll stay married to the same person for the rest of her life." "She´ll have two children... and four grandchildren." "And, when they grow up... only two of her eight great grandchildren... will remember what her name was." "In Britain, she´s likely to live for 79 years... in France, 82... in north America, 80... and in Africa, only 55." "By that time, she´ll have walked over 22,000 km and talked for 12 years." "It´s an amazing list." "In fact, no life is an ordinary story." "We will each, in our time, do an incredible amount." "The driving force behind everything we do... is the most complicated organ in our bodies... and also the most mysterious:" "it´s our brain." "Driving a car is something that people everywhere do... in the course of their everyday lives... driving a rally car is quite different." "The very first time you climb behind the wheel... you wouldn´t know exactly what to do... but it seems we can pick up the basics pretty quickly... and with a couple of lessons and a few hours of practice... we can perform some of the new functions... almost as if we´re on autopilot." "And it´s our brains that allow us to do that." "That´s what brains are so good at:" "managing things without us even being conscious of them." "Your brain is doing that right now." "So, driving a rally car means learning about a dozen new tricky things." "But at this very moment... your brain is literally doing tens of millions of tasks... just while you´re watching television." "To put it another way... it´s as if you were driving not just a rally car... but every car, bus, motorbike, taxi and lorry in the country... all at the same time." "And you just thought you were putting your feet up." "To see how busy your brain really is... you´ve got to look at the world differently." "Everything that´s alive and quite a few things that aren´t,.." "gives off heat." "That´s what you´re looking at now." "Every part of your body is burning up energy and creating heat... as it goes about the business of being you." "But the hottest bit of you is up here." "Your brain is burning up more energy than anything else in your body." "Almost a fifth of all the calories you eat and drink." "And it uses up almost the same amount... whether you´re concentrating on something really difficult... or just wondering whether to put the cat out... because day and night... your brain is challenged with the most difficult task it will ever face:" "keeping you alive." "Right now, for instance, there are quite a few things on your mind." "Tonight´s dinner, for example." "For starters, your brain is co-ordinating a major haulage operation." "Even though the route is usually downhill... food doesn´t fall from your mouth to your stomach." "When your brain tells you to swallow... it triggers waves of muscle contractions." "They squeeze things along in your oesophagus... at around four centimetres per second." "The first scheduled stop is the stomach." "It´s essentially a biological liquidiser." "Its lining is covered in delicate folds... which allow it to expand with each mouthful." "Inside, a mixture of enzymes and hydrochloric acid... start to digest your food." "And very probably, your dinner´s still in there." "It churns away for about four hours." "Soon, it´ll be released into your small intestine and... at a cue from your brain, bile will be added." "This will help you break down fats." "You´ll be carrying tonight´s dinner for about 24 hours." "So I hope you liked it." "When it does finally leave you... it´ll take around 25 grams of dead cells from your gut with it." "But don´t worry:" "you´re constantly replacing cells from head to toe." "Your brain is managing the body´s workforce... of approximately 50,000 billion cells... and most of them don´t last more than a few years." "Cells are constantly dying... and being replaced by new ones." "Up to a billion new cells for old every hour." "What this really means is that most parts of your body... are in fact a good deal younger than you are." "But your brain is less fortunate." "This is a real image of a single brain cell." "It´s incredibly complicated, like a tiny tree... yet you could fit 500 of them on the head of a pin." "Although brain cells burn out at the rate of about 50,000 a day... not one is ever replaced." "These cells aren´t replaced either." "And they´re particularly special." "Each one has a natural tendency to twitch." "They´re heart cells... and several million of them working at once is a heartbeat." "In this case, it´s your head that rules your heart... as it´s your brain that decides... what rate your heart should be beating at." "The same part of your brain that´s controlling your heart... is looking after the outside of you too." "Your body needs to maintain... a constant temperature of 37 degrees centigrade... and your brain has a range of tricks up its sleeve to do it." "This is skin, magnified 1 ,000 times." "If you look closely, it´s covered in holes." "They´re the openings of tiny ducts." "Tubes, through which sweat can flow." "There are about 65,000 of them on the palm of your hand alone." "If you´re getting too hot, your brain switches on your sweat glands." "As the sweat evaporates, it´ll help cool you down." "And should your brain decide that staying warm is what´s needed... it´s got another plan." "Goose pimples." "They trap warm air near to the skin and so keep vital heat in." "So, all that is being controlled from here, inside your head." "And don´t think you´ll get out of all the hard work by nodding off." "Even when they´re completely relaxed, or asleep... our brains don´t let up." "This strange contraption is covered in electrodes... picking up the brain´s activity." "128 sensors detect tiny signals emitted as the brain cells fire." "This is the pattern produced when you´re relaxed." "Even without a thought in your head... your brainwaves show you´re busy." "The truth is, our bodies are always busy." "They just don´t tell us about it." "What we see as the monotony of our daily lives... when it seems that nothing is really happening... is actually the result of immeasurable activity inside our bodies." "We´re performing literally thousands of different tasks... every second of every day." "And just as our bodies hide from us the miracle of everyday life... so they hide from us an even bigger surprise." "It´s the story of how we came to be the way we are." "And it is an amazing story." "It will change the way you think about your body." "The way we live, the shape we are... even the way we think... was decided for us thousands, millions... even billions of years ago... when the human body didn´t even exist... and planet earth was almost unrecognisable." "This is America´s Yellowstone National Park... over 7,000 feet above sea level." "If you´d been on the surface of the planet earth... three billion years ago... it would have looked something like this." "The earth would have been covered in volcanoes... and billowing vents of steam and sulphurous water." "If you´d been here then... you´d have been present as the story of life was unfolding." "And had you been right here... you´d have been looking at the most advanced life form on the planet." "In this almost boiling water... there are thousands of long, thin strands." "They´re actually colonies of tiny heat-loving creatures." "They´re bacteria." "Once, long ago, this was the most complex form of life anywhere on earth." "What´s so surprising is that it´s still here today... just like it was three billion years ago." "Whilst dinosaurs came and went... and literally millions of other species developed, withered and died out... these bacteria have survived, practically unchanged." "They haven´t changed because their environment has stayed the same." "The water they live in bubbles up from deep in the earth... and so is always the same temperature." "But just metres away, the environment is very different." "Away from the thermal vents, with the ebb and flow of the water... the temperature fluctuates." "Billions of years ago, bacteria were living here, too." "But as their living conditions changed, they changed as well." "From one generation to the next, there were minute alterations." "In themselves, they were almost insignificant." "But these tiny changes started the most amazing process." "Because if you add up enough tiny changes... from one generation through millions of generations, ... you get a revolutionary transformation." "From being simple bacteria... the creatures in these pools became more complicated." "Single cells became groups of cells, ... and groups of cells, early plants and animals." "And the changes continued." "Dozens of species became hundreds." "And hundreds turned into tens of thousands." "Parts of bodies were adapted to meet new challenges." "Great leaps were made." "A fish´s fins, over countless generations... developed into legs, and it became a reptile." "Some reptiles developed feathers, and became birds." "Others became mammals... in every shape and size, from blue whale to baboon... every creature we see on the earth today... including ourselves." "All this happened, it´s the miracle of evolution." "The human body is just one branch in the huge spreading tree of life... that grew from those simple bacteria." "Yet we carry with us... the remnants of what has gone before us in our strange past." "And there is a place we can go to see just one of those remnants... shaped by one of evolution´s truly incredible transformations." "It´s inside our heads." "All we need to do is go and find it." "This is the ear drum... it´s a thin skin stretched tight across the ear canal." "But what we need to look at... lies on the other side of the ear drum." "This device can take us there." "It´s a huge magnet... with a field strong enough to lift a car clean off the ground." "This is a magnetic resonance scanner... and it can reveal, layer by layer, what´s inside our head." "Up till now, this has been the forefront of medical imaging,.., but we´re about to take it one step further." "By putting the medical scans together... we´ve created a three-dimensional picture." "And we can look at any part of the head we want to." "We can see the muscles that make up the face." "The skull." "And the brain." "So now we can take you on that journey into the ear... in a way that´s never been possible before." "This time, we can fly straight through the ear drum." "We´re now inside the head... and at last we can see what we´ve come here to look at." "On the right, it´s the ear drum again... but we´re looking at it from the back... and attached to the middle of it is a bone." "Though it´s towering above us, it´s actually tiny:" "about the size of a grain of rice." "It´s the first in a chain of three bones... which transfer the vibrations of the ear drum... to receptors in the cochlea." "They are the smallest bones in the body... and they´re perfectly engineered to perform their task." "Yet these bones will reveal how evolution has transformed us... because they were once something completely different." "Let´s go back, even before birth... and the bones will tell us their story." "A baby, just days before birth." "Inside its head... its ear bones are already the same size as its mother´s." "They´re the only bones in the body that will never get any bigger." "Now we go backwards... rewinding the nine months of our development." "At first, the foetus just gets smaller." "The whole of the last six months of pregnancy... are devoted almost exclusively to growth... to getting bigger." "This means that at three months... although it´s only an eighth of the size it will be at birth... it´s complete, a tiny version of the child that will be born." "Now let´s look at younger and younger foetuses... eight weeks... seven weeks... six weeks." "We are actually witnessing something amazing... because at certain times in this early development... our human embryo betrays the shapes of the embryos... of some of our distant pre-human ancestors." "In other words, what we´re looking at now... is like the embryo of a creature we evolved from... millions of years ago." "It´s just as if we are journeying back in time... virtually rewinding evolution... to show episodes in the history of life." "If we use the magnetic scanner... incredible detail is revealed." "We can see right through the skin at the brain... and the spinal cord beginning to form." "And the beginnings of an eye, behind the emerging hand." "Like some of the creatures that preceded us on the evolutionary tree... it has a curved spine." "And what might be a tail." "And those amazing ear bones we saw earlier... are taking shape on the outside of the head." "The cells that will make them are located here:" "tiny grooves, almost hidden behind that hand." "Millions of years ago... the embryo of a distant ancestor of ours... would have shared with us many of these features." "As well as giving rise to us... it gave rise to all sorts of other creatures... and in those creatures... these features we´re looking at here... have evolved quite differently." "We can actually see it happening with the ear bones... because those very same grooves... that in us will become our ear bones... in this creature become something else entirely." "This is the embryo of a fish." "Here is its heart." "And it, too, has a curved spine." "And the tiny grooves, here... just a fraction of a millimetre long... have evolved to become not ear bones... but supports for its gills." "So, some time, long, long ago... we shared a common ancestor with all these." "And like them, this ancestor too... had little bones around its gills which helped it to breathe." "But as we´ll evolved... these little bones were adapted for an entirely different job:" "to become the intricate mechanism of our ears." "And our ear bones are not the only things... to have been transformed in this way." "Such apparent miracles are, in fact, all around us." "The rest of our ears, that allow us... to balance and walk upright, as well as hear... our limbs and hands, our whole body... has been shaped by the process of evolution." "Everything about the human body has been inherited and adapted... from something our ancestors had a long time ago." "Even though they may have used it for something entirely different." "We are recycled from the past." "Once we begin to understand... the source from which our bodies are derived... the way we look at ourselves can never be quite the same again." "So every part of the human body bears a shadow from our distant past." "Evolution has adapted our bodies from those of our ancestors... all the way back, since life was as simple as that... in the steaming pools of three billion years ago." "It is incredible... and it´s incredibly hard to believe, too... because although we´ve changed so much... we don´t actually see any of those changes happening." "Generation after generation, we just look the same." "The problem is one of time." "The periods over which even tiny changes happen... are so long they´re almost beyond our imagination." "But to make sense of those time periods... to see them in some perspective... we´ve come here... to a cave deep in the French Pyrenees." "In the middle of the last century... a bookseller from the nearby town of Toulouse... used to visit this cave... and as a hobby he searched for bones... and evidence of prehistoric remains." "And he did this for some 40 years." "And then, late in the afternoon on June 1 1th 1905... he set off for home, but went by a different route." "And as he passed this wall, something caught his eye." "He lifted up his lamp... and this is what he saw." "Stencils of human hands, from nearly 30,00 years ago." "They are amongst the oldest images made b human beings on the planet." "They´re six times older than the pyramids in Egypt... and eight times older than Stonehenge." "Quite what they signified to the people who made them... no-one knows." "They were a stone-age people... and they came here at the coldest part of the last ice age." "But further inside the cave are the most interesting images of all." "It is thought that these stencils here... were made by someone no bigger than a toddler... a child in a primitive world... the son or daughter of somebody who we would think of as a caveman." "And yet, if we had taken such a child when it was a baby... and brought it up in our own home... it would be indistinguishable from one of our own children." "Because by the time these people... pressed their hands against these walls... all the changes which make us what we are... had already happened." "The evolution of the human body was... to all intents and purposes, complete." "If the child who made these... were raised in one of our own families... it would look the same... it would talk the same... and it would play the same computer games... and it would grow up wanting to be a doctor... a footballer, or maybe even an astronaut." "But what´s even more amazing to me is that... although we´ve changed so little in so many thousands of years... each of us changes so much in just one lifetime." "We tend to think of growing up as just getting older and bigger." "But actually, as we make our way through life... our bodies change much more significantly than we realise." "In fact, we change just as dramatically as a caterpillar." "A caterpillar is an eating machine... and that´s just what it needs to be... to stockpile the energy it will need to reproduce." "Yet to meet a suitable mate... it may have to travel many miles... and it´s hardly equipped for that." "But evolution has provided the caterpillar with a solution." "One creature is recycled into another." "A new challenge has been met with a new answer." "Our bodies too face different challenges in life... and we are re-worked to cope with each of them." "From the moment we are born we are changing... and adapting to life´s demands." "Aaaagh!" "Well done." "And every change we make follows a plan drawn up for us... by the millions of generations that have gone before." "In this series, we´re going to show you... the stunning science of these changes throughout life." "How our brain cells are wired up when we´re children." "How hormones transform us at puberty." "What changes happen inside our bodies." "How our muscles become stronger." "How our brains mature as adults." "How our bodies continue to alter throughout our lives." "And by using the very latest techniques... we will show you things you may never have seen before... in incredible detail." "The hairs that transmit sound inside our ears." "The taste buds on the surface of the tongue." "And one of the largest cells in the body: the human egg." "But if we were to tell you just the science of these changes... we would be missing the most important thing of all." "This is the amount of tears... that an average person cries during a lifetime:" "just a fraction under 65 litres... or, to put it another way,2 about 1 ,850,000 drops." "So what do we know about them?" "Each tear weighs 35 thousands of gram... and is about as salty as this part of the river Thames, in London." "Tears are produced by a gland just above the eye... which is literally squeezed when we cry... and the tears come down six tiny tubes, about the thinness of a human hair." "As far as we can tell, of all the animals in the world... only humans actually cry when we´re hurt or upset... about 28 drops each time." "Though they´re 99%% water... tears also contain about 80 other ingredients... including sugar and antiseptics." "But what´s the most important thing to know... if all these were your tears?" "It´s why you cried them." "How many of these thousands of droplets were shed in fits of anger?" "How many in pain?" "How many in love?" "In grief?" "How many in sorrow?" "How many were shed by a baby?" "And how many by an old man, facing the end of life?" "The truth is, a knowledge of the science of life... is only made complete by a knowledge of those living it." "The human body is not just a biological machine... it´s much more than that, it´s a person." "And in this series, it´s people that will tell us... what the body´s ever-changing story really means." "Take Zak, for example." "Having already mastered the complexities of crawling... he´ll be taking his first steps." "When he realises, he´s let go of something... and he´s standing on his own two feet... he kind of realises what he´s doing and he gets scared and... he loses balance completely, you know." "But he tries, he´s a hard trier." "Keeps going for it." "When it comes to growing up... 12-year-old Beatrice will ride the roller coaster of puberty." "When you´re a teenager, apparently you go bolshie... you get your periods, you get pubic hair... you get taller, you get... sort of... oh, I get the hips, I think it is, I can´t remember." "It´s painful to run, I can tell you that,.." "because what happens up above, you have to start wearing a bra... sorry, I had to mention it... it gets really painful to run." "Month by month, Jeff and Phillippa will share with us... perhaps the body´s greatest miracle." "I just marvel at the fact that all of this is gong on... with no real intervention from me... it´s just my body taking over and doing it all." "Well, I´m not in control of it at all, it just all happens." "In adulthood, we reach the peak of human achievement." "Marcia, an astronaut, has scaled the heights." "There is nothing in our experience... genetic, metaphysical, emotional, psychological experience... that prepares us for being off the planet." "You can look at all of the pictures and videos that come back from space... and there is something about looking out the window... that is not describable." "And we´ll be living through the ravages of ageing... with 76-year-old Bud, and his wife Viola." "They live and work on a farm in the mid-west of America." "What I remember about Bud, he had the prettiest, waviest hair." "That´s different now, isn´t it?" "Yes, it is." "And his skin was smooth, no wrinkles... and he didn´t have any little pot here." "And in our last chapter, as his body slowly succumbs to cancer..." "Herbie will take us on his final journey." "I know I´ll never see this film in my lifetime." "But I like that everybody see... that a human being can manage an illness like my illness... and everybody can see in this film... there is a way to make the best from the end of your life." "So this is the story of the human body... a tale of fantastic changes and amazing achievements... written over millions of years of evolution... and told afresh by each of us during our lifetime." "It surely is the greatest story ever told." "And each of us has a part in it." "From new-born baby upwards... this line follows the journey we will all make through life." "Each person is one year older than the last." "All of us have a place somewhere along this line... looking forward, looking back... or perhaps a bit of both." "Seen like this, stripped of the trappings of wealth and status... we have one thing in common... one place we all inhabit, one vehicle we all travel in:" "it´s the human body." "In the coming weeks... you´ll be seeing your body in ways you´ve never seen before... and perhaps, you´ll share my sense of wonder... at how it shapes us all into who we are." "You´re looking at a baby´s heart." "It´s beating a hundred and twenty 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." "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." "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." "Over a hundred million acts of sexual intercourse... take place each day in the world." "These result in around nine hundred and ten thousand conceptions... and nine months later four hundred thousand 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 at 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 so looks so elegant, you´d think it was simple." "But you´d be wrong." "These are the sperm from just a single ejaculation." "Amazingly, there are about 500,000,000 of them." "With just this one ejaculation... it should be possible to impregnate all the fertile women of Western Europe." "In actual facts, 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 squeeze 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 we´ll look at that time afresh." "Over a single day... and over three hundred 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." "And I think we decided fairly quickly not to have them straightaway." "Yeah, but it was never a sort of issue... as to whether we would or we wouldn´t, I think." "We just both assumed that we would." "It was something that didn´t have to be discussed... as a 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." "I assumed very much that as soon as Phillippa came off the pill... getting pregnant would be a piece of cake." "But I´m not sure that´s the case." "Well I definitely thought... as all my previous experience has been about contraception... ad how important it is,.." "and 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 my opinion at the moment is that... I wonder how people actually do get pregnant." "It seems very difficult." "And Phillippa´s right, it is difficult." "There are only about thirty 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." "There 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 four hundred 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 twenty four hours to be fertilised." "After that it´ll die." "And to be fertilised it needs to meet a vital ingredient:" "Sperm." "What´s the best way to make sure... a sperm meets an egg in those vital twenty four 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." "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." "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 five hundred 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." "Or 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." "Only 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 fertilised 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 unaware of the changes going on inside Phillippa´s body." "Hour after hour the fertilised 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 fertilised 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 as a leech." "It´s a parasite." "It takes whatever it needs to live... by sucking the blood of whatever it can latch onto." "As it sucks blood, it takes all that it needs." "It literally lives off its host." "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... and I woke up and I suddenly had this urge... to try out the pregnancy test kit." "I was sort of 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:" "Oh I think, we have lift off almost, it´s been a success." "And we did wander around for a couple of days after that... grinning at each other like Cheshire cats." "The first reaction was probably relief... and then the jubilation and the joy set in." "I think because I was very anxious about it... and had we waited too long... it was nice to know that it had in fact worked." "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 fertilisation." "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." "The 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 palm prints 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." "For the rest of pregnancy it 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." "Only six cm long." "It weighs about fourteen grams." "The weight of a small plum." "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." "That was the first thing I noticed... which I wasn´t prepared for." "Because 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... well not worried but a bit sort of surprised that it was so immediate." "Because you know towards the end that they would inevitably get large... but I didn´t think it would be right 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." "But by far the most common complaint is feeling sick." "Sea sickness is truly miserable." "It´s maybe the closest we ever get... to what three quarters of all women feel during early pregnancy." "Morning sickness." "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." "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." "And how would you get any peace... when above you two cavernous lungs worked day and night?" "And worse still... right next to you would be the biggest distraction of all." "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´s 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." "Okay, lets show you your baby before I do anything else." "So we can see it´s head, body... heart beating away there in the middle of the chest." "Oh, I see it now!" "There you go... ..see the fingers there piano player´s hands." "Think baby´s just having a yawn at the moment." "Told you it would always be tired like me." "Plenty of time to rest while it´s in here." "It´s really the first time I´ve realized that you´re actually pregnant." "It´s amazing that suddenly I´ve got to realise... that there is actually something in there." "It was just so moving as well l was... I mean it was very emotional." "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 and everything... it´s great really to know that everything´s all right." "it´s gonna be incredible to show this to my mum, I can´t wait to show her." "Because technology´s incredible," "She never had an opportunity to see this sort of things... but here we´ve got pictures of our future child." "So this is what we know of the foetus´s 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." "Sounds, for instance, may be felt through the skin... as well has heard by the ears." "Likewise, changes in the fluid that surrounds a foetus... will be as much smelled as tasted." "But 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." "Really, our 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 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´s in." "Which way round it is?" "Yeah, I can´t work out whether it´s a bottom... or what´s that keeps poking out." "Oh what I was feeling earlier on?" "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." "Because 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 piece... 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 roomful of technology cannot begin to compare... with the capabilities of this... because this is a placenta." "It´s a kidney dialysis machine, an artificial liver... and a heart-lung machine all rolled into one." "It´s a go-between." "It´s what allows mother and foetus to live together... and it´s probably the most fantastic thing about pregnancy." "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 back ache." "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." "That was a little movement." "Which bit was that then?" "What are you doing?" "Where are you trying to get to?" "You´re soon gonna run out of space, you won´t be able to do that." "I´m not sure that 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." "I mean all men must go through the same sort of thing." "You feel fairly helpless." "And while all the changes are going on to Phillippa... physically, mentally, emotionally... the same sort of thing´s happening to me... but I´m only looking very much from the outside." "And there are times that I wish that I could... I could feel the physical side of things." "So that I could understand it a little more." "But 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." "At the moment Jeff and I are just kind of continuing as usual... which may be a bit foolish." "Every now and again we sort of look at the calendar and panic and think... lt´s only eight weeks, it´s only seven weeks or what have you... as if we have this great big list of things which we want to do... which we don´t." "I think it´s just sort of we know that the change is coming... and that every day it´s approaching... and there´s no sort of turning back." "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." "When I´m not, 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." "Our imperfections are simply problems inherited from our ancestors." "The great triumph though is that we´ve 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." "Our 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." "...listening all 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." "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´s doing extremely well." "We´re just hoping that the contractions are making the cervix dilate." "At first the contractions aren´t moving the baby... they´re 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." "Once 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... lets 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." "Well done." "Well done, the contractions are going on, Phillippa." "Okay." "...sit on the edge of the bed and then just put your... 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!" "...have to push again Phillippa..." "That´s excellent." "Well done, that´s it keep it there." "Right come on Phillippa lets have a really good push." "Put your chin down." "That´s it." "Take a breath." "One more push Phillippa if you can, because it´s so close." "That´s it, you´re doing." "Well done!" "Oh well done 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." "Childhood, from new-born baby to infant." "From toddler to the first day at school." "To crawl, to walk, to talk... to become an individual." "It is four years of miraculous achievement." "Never again will the human body change so fast or learn so much." "This is the story of that remarkable time." "It all begins with the most treacherous journey of our lives:" "from our mother´s womb to the outside world." "As recently as the late nineteenth century... one in twenty babies died during birth." "Death affected everybody including royalty." "At Windsor Castle, in England... there is a memorial to Princess Charlotte and her son." "Just one year after her marriage in 1816 she was expecting a baby." "Tragically the birth was a disaster." "The baby boy became stuck inside his mother." "After two days and two nights of labour... the unborn prince was dead... and a few hours later Charlotte died as well." "Their deaths meant the crown eventually passed to Queen Victoria... and the rest is history." "With modern medicine Princess Charlotte almost certainly would have survived... and her little boy would have become king." "Today in the western world very few babies will die." "But that journey down the birth canal, just ten centimetres in length... remains as fraught with danger as ever." "Go on Jane." "For nine months the baby has been fully equipped for life... in the warm liquid world of the womb... relying on its mother for food and oxygen." "It´s in for a rude shock." "Big push Jane." "As the baby is squeezed down the birth canal... dramatic changes have to happen." "The key to success is the trauma of the birth itself." "It´s so severe the baby has adrenaline levels... even higher than that of a person suffering a heart attack." "This rush of adrenaline will kick start the baby´s breathing." "Well done, that´s brilliant." "Here he comes." "Yet even now, during birth... the baby´s windpipe and lungs are still full of liquid from the womb." "If they aren´t quickly emptied it will drown." "The fluid drains away as it´s absorbed into the lung walls." "Air rushes in." "Life-giving oxygen can enter the blood vessels of the lungs." "The first breath triggers further upheavals inside the tiny body." "That´s it Jane." "Well done sweetheart, well done." "That´s.. a baby boy..." "Well done." "Remarkably, even at this late stage... the heart of the baby is not yet ready for life outside the womb." "In one of the interior walls of the heart there is a hole." "This opening was vital when the baby had to pump blood to the placenta." "Now it´s a liability." "Blood flowing through a newly opened vessel... will slam shut a flap of tissue to seal the vulnerable hole." "It forms a solid wall... and the fur chambers of the heart are finally complete." "In an adult such major changes would require open heart surgery... but here they are happening instantaneously... and unseen inside the baby." "This is the miracle of birth." "I´m gonna cut his..." "Can Richard just cut that cord?" "It´s a boy, Bob." "Go for it, Richard." "The umbilical cord, the last link to his mother, is cut." "Bob´s first challenge is to keep warm." "A heat-sensitive camera reveals the coldest parts as blue." "Bob´s toes and nose suffer most." "The delivery room is fifteen degrees colder than his mother´s womb." "He looks fine." "Wheehh!" "A special type of fat is concentrated on his back and around his chest." "This baby fat can be broken down to release emergency heat." "But for the first six months of life..." "Bob´s ability to control his temperature is very limited." "For the moment he relies on blankets and cuddles." "He´s shivering a bit now." "His little lips going." "He´s cold... cold..." "He´s got dark hair hasn´t he?" "Those little marks will become..." "Take no time at all." "It´s all a bit of a push wasn´t it?" "Bob´s tight squeeze through the birth canal... has left his head an odd pointed shape." "His skull is so pliable because... the 22 different bones that make it up haven´t yet fused together... leaving holes between the bone plates." "Bob would never have made it out of the womb... if his skull hadn´t evolved to be this way." "From now on Bob will live... under the watchful eye of his proud parents, Jane and Richard Jeffers." "His hazardous journey into the world is over." "Oh thanks Richard." "That´s brilliant." "...and he´s fine, he´s really settled." "It´s just amazing to see you know that he´s perfectly formed... in absolutely you know every way, his arms, his legs." "He´s got quite a tidy little nose." "He´s got a nice mouth, he´s got quite a wide mouth." "Everything´s just perfect, it´s... it´s just a miracle." "You don´t see that they´re wrinkled up and all those other things." "His face... his face looks really quite well established for a small baby." "I mean he´s got quite a lot of character." "In a strange sort of a way it looks like a little old man." "Although Bob is helpless he has a fantastic survival strategy." "Parents find their new baby irresistible." "Oh Bob, is that nappy bothering you?" "Come on." "They do control you to a point, I mean, their demands are paramount." "If they cry and want feeding then basically you´ve got to do that." "If they need changing." "You can´t ignore their needs because they´re totally dependent on you." "Hey this is the best bit isn´t it?" "Bit of fresh air to that bottom." "It´s almost as if Bob has put his parents under a spell." "Bob´s first picture." "Over a period of six months we follow Bob´s rapid development." "Just a few weeks after birth he was a bundle of reflexes." "A handy set of automatic responses that help him survive." "Can he hear you?" "Yes, he´s startled by loud noises and he can definitely hear me." "A young baby will try to grip with his hands anything he touches." "Young apes grasp onto their mother´s fur." "But even in hairless humans... this grasping reflex can be useful for holding on." "He doesn´t seem to want to go much more than four hours but you know." "I´m just going to check his reflexes, okay?" "The reflex is activated by any touch to the palm." "Here, the baby´s hand has grasped a finger." "Inside the hand you can see the muscles... that even just after birth can support the weight of the baby." "Ironically the hardest thing for babies to learn is to let go." "Their fingers have to be prised open." "And Bob´s toes will try to grip as well... a throw back to our ape-like ancestors... who held onto things with their feet." "These reflexes are completely involuntary." "They require no more conscious control... than the contraction of the eye´s pupil to light." "Are you ready?" "Ready for your milk." "Good." "Another reflex helps Bob find food." "Although he doesn´t know where food comes from... whenever something brushes his cheek... he automatically turns his head from side to side and parts his lips." "This is the rooting reflex." "He just finds it himself you know." "You´d..." "I mean he´ll find it... you know, you just need... to put his head somewhere remotely near and he´s there sort of thing." "And that´s not all." "The milk that´s produced in the mother´s breast... can be activated merely by the sound of the baby crying." "That´s a lovely boy." "Bob not only manipulates his mother´s behaviour but also her body." "What a face." "Got a full tummy there." "New born babies have another reflex, which is much more mysterious." "In fact, it´s an ability so odd... that for many years people didn´t even know we had it." "We have this reflex only for a short time." "Perhaps the six months, and what an ability!" "It´s called the diving reflex, because it stops the baby from breathing under water." "The mouth can be wide open... but inside the baby, the top of her lungs is sealed off... and any water diverted down the oesophagus into the stomach." "Perhaps more amazing are the baby´s movements." "Not only do the arms and legs move in a co-ordinated stroke... but the torso flexes enough to propel him through the water for over a metre." "However, after a few seconds... they all need adult help to regain the surface and the vital next breath." "Some people believe these abilities come from a long lost ancestor... who spent most of its time in the sea." "Others think it is a hangover from our life in the liquid-filled womb." "The truth is, whatever the origins of this remarkable reflex... we might never get to the bottom of it." "it is, for the moment at least, a delightful mystery." "That´s it." "As the baby´s mind matures... these involuntary reflexes are suppressed... by conscious thoughts and movements." "This has already happened with Max, Bob´s three year old brother." "But what´s really interesting is... that the reflexes of babyhood stay with us all our lives, hidden... and very occasional they can re-emerge many years later." "People who are afflicted by the dementia of old age... sometimes lose conscious control of their body." "When that happens... remarkably the grasping and rooting reflex are restored after 80 years... life turning full circle." "In the buzzing booming world... both reflexes and conscious thoughts depend on the senses." "But at first Bob can see little." "Contrast is poor." "Anything beyond half a metre is out of focus and blurred... and he may even see double." "One of the reasons Bob is so bad at focusing... is hidden inside the eyes." "A very young baby does not have proper control... of the muscles that change the shape of the lens." "The lens, here coloured white... is fixed at one set shape." "To focus on objects far away... the tiny muscles around the lens need to stretch it into a thinner shape." "It´ll be a while before Bob learns to do this." "Are you gonna try, yes?" "Clever boy!" "By two months, his vision will have improved." "He seems to like looking at faces best... and it´s at this time he will first smile." "A magic moment for any parent." "Well at first I thought no he can´t be smiling, not yet... because he started at about just over three weeks... and I thought no, no it must be wind..." "And then I realised that he was actually smiling back at me... and it was, it was really good, it was like oh he´s smiling, he´s smiling!" "Smiling and recognising a smile are crucial milestones." "So a team in London are finding out... what´s going on inside the head of this baby girl... to see how she does it." "You´re a very good baby." "Very smiley." "They measure the electrical activity in the brain... when she looks at different faces." "A scowling face." "A smiling face." "And an upside down face." "The patterns of brainwaves prove that the baby first sees it as a face... right way up or not." "And then a fraction of a second later... she checks out what emotion is showing." "And these two tasks actually happen in different parts of the brain." "You might assume a baby´s brain... is just the same as an adult´s, only smaller." "But it´s not." "A baby´s brain is nowhere near finished." "New connections between the hundred billion brain cells... are being made all the time." "Throughout babyhood the brain is sculpted... so our experiences in our first few years... will determine the bran that we have as adults." "This developing brain is so demanding... that over half of all the food Bob eats... goes to driving it." "To supply this much energy... it´s essential that he moves on from milk." "To deal with solid food... things are stirring underneath his gums." "His first teeth will grow up from tiny tooth buds... that have been hidden in his jaw since long before he was born." "But they won´t start to burst through his gums... until he´s around six months old." "For the first time, over forty days... this dramatic event has been filmed." "No wonder babies cry when their teeth come through." "At birth Bob was a tiny bundle of reflexes and flailing limbs." "Over the following six months... he has grown quicker than he ever will again." "He has more than doubled in size." "But he hasn´t just been putting on weight." "What is less obvious is that his mind has matured." "For the first time he can control his hands... and reach out to grab objects." "He is turning his desires into actions... a sign of his burgeoning personality." "A baby at this age is soon ready for the next key advance." "Mobility." "One stage ahead of Bob is Zak Troullous." "Zak is already seven months old and lives in London." "Over the next few months... he´ll take his first steps and speak his first words." "But for now that´s all in the future." "He seems to be developing, you know, very normally." "And that´s great." "Has he tried to pull himself to stand or anything like that?" "When he´s sitting down like he goes forward... but he´ll fall on his face." "So, he´s a bit scared." "Right." "It´s a good time now while he´s sitting... to think about making sure that the environment is safe for him." "Because everything tends to go straight from hand to mouth." "Oh yes I know." "...and he´s trying to chew at the moment." "Zak´s mouth is the most sensitive part of his body." "The tongue is teeming with nerve endings." "That´s why babies are so keen... to use their mouths to explore the world." "But Zak´s scope for exploration is limited." "He still relies on his parents to get around." "Things will have to change." "We normally associate crawling with reptiles." "Think of the sprawling waddle of a lizard." "But it´s actually a powerful way of getting around." "All movement of the human body... is surprisingly complicated and difficult to analyse." "But if you really want to understand motion... analysis is what you need." "That´s what these little markers stuck on this baby are all about." "They can be tracked by computer... to reveal the underlying motion of the skeleton." "Dozens of joints and bones moving in harmony." "This baby is doing the diagonal crawl, moving opposite limbs together." "Right arm left leg, then left arm right leg." "The arms absorb the shock of impact... while the power is provided by the legs." "The top speed of a crawling baby is about two kilometres per hour." "And the average baby crawls perhaps two hundred metres a day." "Motion capture analysis has identified seven different types of crawling." "The elephant crawl is where just one limb is moved at a time." "But the diagonal crawl is the most popular." "It´s extremely efficient, combining stability with speed." "This crawl takes a while to perfect, as Zak is finding out." "He´s crawling slowly." "But he´s still got that wobble." "Yeah, each day goes by he´s getting a bit better now." "Bad co-ordination." "You know once he gets down." "He needs a bit more confidence really." "Like before I put him down and I gather a few toys... and he´ll be playing... and I´ll go into the kitchen and do something for a few minutes... and I know he´ll be put there and he won´t move." "But now because he´s crawling he´s going down to the stairs... and you´ve got to keep an eye on him every second of the day." "Until he started crawling Zak had no fear of heights." "Now he is increasingly wary." "Okay, we´re gonna put your weight on." "At a university in America..." "Karen Adolph experiments with crawling babies... to discover how they deal with treacherous slopes." "As a further challenge the babies are weighed down with two kilograms of lead." "They then meet the apparatus." "Mother tempts her daughter from the other end of the ramp." "Come on Natalie." "Once she´s scoped her target... the baby visually assesses the slope." "She confirms the severity of it with careful touches of her hands." "Karen has discovered that... they can gauge the angle of a safe slope to within just two degrees... a tiny fraction of the slope overall." "If they decide it´s a bit too steep they´ll adjust their crawl... maybe even coming down backwards." "Crawling is not just about how to crawl... but what´s sensible to crawl down." "If it´s way too steep. .." "the baby will wisely avoid the drop altogether." "However the real revolution in getting around is still to come." "Zak, are you gonna walk over to daddy?" "Eh, are you gonna make it?" "Zak is eleven months old... he´s about to express what human beings have felt... throughout three and a half million years of evolution... an overwhelming desire to rise up on two feet and free the hands." "Are you gonna walk over to daddy?" "Zak already has the strength to stand up with a bit of support." "But his ability to walk comes not just from his legs... but also from deep inside his ear of all places." "At the end of the ear canal are the bones we use for hearing." "Behind these is the balance organ." "The balance organ is a miracle of engineering... made up of three circular tubes full of liquid." "Anchored to the inside walls of these tubes... are tiny hairs." "As Zak moves, the hairs also move... telling him the position of his head." "The three tubes each have their own orientation... which detect the three basic types of movement in space." "Roll, pitch, and yaw." "This device will allow him to take his first independent steps." "When he realises he´s, he´s let go of something... and he´s standing on his own two feet... he kind of realises what he´s doing... he gets scared and.... he loses balance completely, you know." "But he tries, he´s a hard trier." "Keeps going for it." "It´s been a long twelve months for Zak." "Learning to crawl and then get up on two feet... have been key achievements." "Zak can now walk tall on his own." "Zak is a new experience junky." "As eating is food for physical growth... so experience is food for brain development." "Zak may be walking but he faces another barrier to further progress." "Imagine what it´s like for an infant to understand so very little... of what´s going on around it." "To feel lost and excluded from the social world." "The closest we get to it is when we go on holiday abroad." "To go shopping in the markets or to book a taxi... can be a bewildering experience in a foreign country such as Egypt." "Trouble is, you can only get so far with mime and pointing." "Do you understand English?" "Can you take me to the pyramids?" "As a child one thing you lack.... is an accurate way of explaining your desires... exactly what you feel... what you really want... or any way really of telling your parents what to get for you." "What you need of course are words." "Every human culture has depended on them... be they spoken or written... like these hieroglyphics." "Words and language are the most important thing a child will ever learn." "Not just words to describe things you can point at... but words to describe abstract things:" "your past, your future... your fears, your hopes." "Words to describe discoveries and ideas." "To communicate them to other people, down the generations... ever expanding the wealth of human knowledge and experience." "The whole world we have built is built upon language... and yet it all begins so simply." "Mama." "It seems a miracle that fifteen month old Zak... can begin to master the complex power of language... an infinitely flexible symbolic system... and yet still needs nappies." "Bravo." "Even more impressively Zak is learning English... and his parents´ other language, Greek." "When babies first learn to speak... they use a completely different part of the brain... from adults trying to learn a foreign language." "That´s why it´s so natural for babies and such an effort for adults." "But it´s not just Zak´s brain that gives him his power." "A new born baby has a vocal track just like any other animal." "The larynx, a pipe at the top of the lungs... is positioned high up right at the back of the throat." "It sticks up like a snorkel, above the flow of milk to the stomach." "This ingenious arrangement allows the baby to breathe... and suckle at the same time." "But with the larynx so high... it can´t perform its major function in life:" "speech." "By the time Zak is a year old... the larynx needs to have dropped a whole three centimetres lower." "Zackie, where´s mummy?" "The lowered larynx now lives up to its other name, the voice box." "With more space at the back of the throat... the voice box can make an extraordinary variety of sounds." "As air passes through the gap between the vocal cords... it causes them to vibrate." "The tighter the cords are the higher the pitch." "And the final sounds are shaped by subtle movements of the tongue." "To create just one recognisable word..." "Zak has to co-ordinate over thirty different muscles." "Unfortunately this lowered voice box... makes humans especially vulnerable to choking on food." "As a species however this occasional problem... is outweighed by the power of language." "The human larynx has evolved so that... the way it changes suits each stage in life." "Zak can finally communicate." "Over the previous year Zak has progressed from baby to toddler... but the pace of change does not let up." "Look ahead another year and a child will have raced ahead again." "My name is Moira." "Oh lovely!" "Look at that." "Very good." "High five to both of us." "This little girl is two and a half years old." "Moira lives in a peaceful suburb in New Jersey." "Like all toddlers she is learning a staggering ten new words a day." "It did seem quite quick... that she was able to communicate or to describe things in detail." "It seemed really fast." "Thank you." "At one point you think that she´s able to just sort of... react with words... and then it´s amazing when she´s able to take words... and think about the future and what could be possible." "You know what this is over here?" "What is it?" "Turkey." "Yeah, you like turkeys?" "Can you make the noise?" "Gobble." "Gobble." "Gobble." "Gobble." "Moira has never seen a baby deer before... and doesn´t know the word for it." "This is the first time she will ever say it." "Do you know what to call one of these things?" "Well some people call them bambis, but that´s after the movie yeah?" "They´re called a fawn." "Can you say that word?" "Fawn." "Fawn, yeah." "Not only is Moira an enormous sponge soaking up new words... she knows automatically how to construct them into proper sentences." "Children have an instinctive knack for language... and get the grammar right virtually all the time." "But their occasional mistakes are telling." "It´s almost always when the grammar is irregular." "Moira if I had one mouse... and I had another mouse I´d have two what?" "Two... two mouses." "Two mouses?" "There´s another word for the plural for mouse isn´t it?" "What is it do you remember?" "It´s be two... mi..." "Mice." "Two mice, that´s right." "Very good." "Good job." "Moira created the word mouses herself... by just adding an S." "It´s impossible for her to have imitated the word for an adult... because they never use it." "Instead she applied the logical rule for making a plural... and has to be taught the exception." "So, why is it that toddlers can learn language so rapidly." "The theory is that throughout evolution... little children have always faced grave dangers." "The quicker they learnt language... and the better they understood the warnings... the more likely they were to survive." "In just the same way that a clam has evolved the tough shell to protect it... we have evolved language as our defence." "Guys, you need to be careful of the water, come back up here." "But language is not just a simple one-off trick like the clam shell, it´s power and flexibility are unique." "It´s given rise to our rich social world... delivering us a decisive advantage over other animals." "Alongside language, children learn another skill... a skill adults rarely give much thought to." "When we look into a mirror... we realise that it is ourselves reflected." "It´s so simple it seems silly." "But in fact, though we take our ability... to understand mirrors completely for granted... we are one of only very few animals... that have any idea what´s going on with them." "A monkey can´t recognise itself in a mirror." "But a chimp can." "Interestingly it´s a skill humans are not born with." "Fourteen month old Julia ignores the red dye painted on her nose." "She fails to recognise the reflection is her... because she doesn´t yet have a proper sense of herself." "Julia lacks self awareness." "Unlike Moira, who is over a year older." "Yeah." "Look at... .Moira also uses words like I, me, mine... proving she is now aware... that she is a separate person from everyone else." "Who´s that?" "You and me." "You..." "And me." "And me?" "Yes." "Yes." "Children of this age have the self awareness... to realize when someone else is hurt." "Moira will comfort her mother." "Even if she is a pretender." "Moira, can I have a kiss right there?" "I need a kiss right there for where the shark bit me." "Oh, the shark gave me a kiss, what a lovely shark it is now." "Unfortunately there´s a dark side to self awareness too." "Bring the shark back, please!" "Bring the shark back, please!" "No!" "The shark is coming back." "Thank you very much." "Moira sometimes uses tantrums to get her way." "This is the terrible twos... when she has the self awareness to recognise her needs... and the language to express them all too clearly." "All the changes in Moira´s view of the world... are taking place because of alterations inside her maturing brain." "Different skills such as language and self awareness... are clamouring for space in particular parts of the brain." "But there´s still something missing." "It´s a series of developments that´ll take two years to perfect... and it´s all about getting on with other people." "James is an active four year old who lives near Philadelphia." "But he is unusual in that he has two brothers exactly the same age." "Sean and Evan." "James, we like to call him our athlete." "He´s very athletic, pretty strong... sort of acts like the older brother... because he is so much more advanced." "Evan on the other hand, he´s different, he´s very moody." "We call him our moody artist type." "And Sean´s the smallest of the three... and I think because of that he learns to compensate a little bit... and so we call him our politician because... he´s used to trying to negotiate for things... and sort of is a little more tolerant of things in general." "Part of getting on with another and dealing with the social world... is learning and complying with rules." "Well we´ve got a set of rules based on their interaction." "You know most..." "mostly like you know..." "No fighting rules." "No playing on the stairs." "No hitting, pulling hair." "No hitting, o fighting, no biting, no scratching." "No, no..." "And if somebody does get out of hand... they do end up in their room by themselves... for some quiet you know sort of time out themselves time." "James." "Were you supposed to be taking those cookies now?" "No it´s not okay." "Are those cookies for now?" "No those are special cookies those are for later." "No, that´s not okay." "Now put the cookies back." "Breaking the rules leads to shame." "Look at the classic hunched shoulders and the drooped head." "James knows he´s done wrong." "He is starting to acquire a conscience." "But no sooner are children taught the rules... than they discover a way to get around them." "Lying starts surprisingly early." "But until recently it´s been considered well nigh impossible to study." "Child psychologist Michael Lewis... has created an ingenious test to reveal more about lying." "He and the mother of the child he´s studying... hide behind a one-way mirror." "I have a toy under here." "I´m gonna uncover it but I don´t want you to look at it." "I want you to keep looking straight ahead." "Don´t turn around, don´t peek." "Gonna uncover it and I´m gonna turn it on, but don´t look." "I have to get something, I left something out in the hall." "I have to go get something so I´ll be back in a minute... but I don´t want you to look at the toy while I´m gone." "Just keep looking straight ahead." "When I come back we can play, but don´t look at it till I come back, okay?" "Don´t peek." "So what do you think he´s going to do?" "I think he´ll lie." "I think he´ll look." "He´ll look?" "Yes." "And then lie?" "Yes." "Okay, lets look and see." "Well he´s holding out." "His eyes are starting to... he´s gonna peek." "Okay." "You know I have to tell you that three year old children... about seventy percent of them peek... and when they peek almost all of them lie." "...did you peek?" "No?" "You want to turn around and play with it now?" "Come on go ahead you can turn around and play with it." "Well you were right." "They peek and then lie about peeking." "And they lie because they don´t want to get into trouble." "And if you think about it, it makes sense." "It´s not only that they didn´t do something right... but they may get punished for it." "And so it turns out that the smartest kids... are not the ones who tell the truth... but in fact the ones who lie about it." "Okay don´t peek." "And it´s true." "At this age the higher your iq, the more likely you are to lie." "To lie deliberately these children have to be aware that... the experimenter doesn´t know whether or not they peeked." "Did you peek at it behind you?" "No." "No, okay." "This awareness that other people... can have different beliefs and thoughts from your own... is not just useful for the occasional fib." "It´s a crucial stage." "All children need to pass it before they are ready for the adult world." "Scientists call it theory of mind." "It´s our human skill of working out what another person might be thinking." "To do it, we need to realise that each one of us... has different wishes and intentions, likes and dislikes." "Another person´s thoughts and desires... are not necessarily the same as yours." "We all do it without even being aware of it... it is the very cornerstone of all our relationships with other people." "But at three years old these children are too young to have learnt it." "The triplets are just four and they have developed theory of mind." "Take hide and seek." "If you think about it it´s quite a sophisticated game." "The boys know that their dad won´t be able to see them... if they hide themselves properly." "They realise that his view of the world can be different from their own." "Theory of mind is even more essential in making sense of stories." "To follow what´s going on in Snow White, the triplets need to grasp that... different people will see the world differently." "And soon Snow White heard someone knocking and went to the window... without even stopping to think about what the dwarves had said." "Most children younger than three will assume that Snow White... has the same knowledge that they do." "That the apple is poisoned and Snow White shouldn´t eat it." "This makes a nonsense of the story." "The triplets though know better." "What was the old woman giving her?" "An apple." "But what was it really?" "A poisoned apple." "Well what did Snow White think it was?" "Sean?" "A present." "A present." "Who was that?" "The mean queen." "The mean queen and what was she trying to do?" "Hurt Snow White." "She was trying to hurt Snow White." "Was it a nice thing to do?" "It was a bad thing to do." "Understanding what motivates others in fairy tales or real life... seems obvious to us.." "but it´s a key turning point in every child´s development." "By scanning people´s brain activity... it´s been possible to identify the part of the brain... where theory of mind develops." "Tell stories that require it... and this important section right at the front of the brain... literally lights up." "In the triplets the brain connections of this area are now almost complete." "Theory of mind is the final piece of the jigsaw." "It marks the transition from babyhood to childhood." "Once a child has made it... the world will never seem the same again." "We will miss them when they go out to school... because pretty much all of our time and energy goes into managing them." "Well, this our favourite song again, can you guys sing along to the song?" "We sort of have mixed feelings like it´ll be great to have some time... but then on the other hand it´ll be pretty scary... to send them out into the world, just to be so independent." "Do you have your backpacks ready?" "Okay hold on, and you´re next big guy." "Have a good day okay?" "Okay." "I´m gonna see you climb those big steps." "Okay, hold onto the rail and have a good day at school." "Over just four years, the triplets have met all the challenges... this new and exciting world has thrown at them." "Bye bye!" "To walk, to talk... to understand the thoughts of others." "They are ready for the next stage of their lives." "What you are about to see is one of the miracles of nature." "The extraordinary transformation... that will turn this caterpillar into a butterfly." "But we human beings go through a biological revolution... that´s just as dramatic." "Over four agonising years our bodies and our minds are transformed." "At the end of it, like the butterfly, we´ll be sexually mature." "This incredible change is called puberty." "Best thing about puberty is that my voice is getting deeper." "Girls start liking you and you start liking girls." "It´s very interesting I like it a lot." "The worst thing..." "God, the worst thing for me is probably the ups and downs of life." "Having to deal with acne and hair and stuff like that." "I don´t have any facial hair that much... so people start to compare me with those who do." "It´s like a roller coaster, you don´t know which way it´s going to turn." "Just dealing with it is a drag." "Unlike caterpillars, these teenage boys have no cocoon to hide in... while they travel from childhood to adulthood." "We all make the journey... and it can be a bumpy ride." "We often have the illusion that somehow we are in control of our bodies." "But it´s really our biology that controls us." "And nowhere is that more obvious than... during the great roller coaster ride of puberty." "And though we may think we know what´s going to happen... nothing can quite prepare us for how it will feel." "It feels exciting and dangerous... and we don´t even know how long it will take." "But the worst thing is, just when you think you´ve got it mastered... suddenly something else happens and your body changes again." "If living through puberty feels like a horror story... the villains of the piece are hormones." "These tiny chemical messengers are beyond our control." "Suddenly hordes of them start racing through our bloodstream... ordering our body to change." "They tell us to switch on to sex, getting us ready to make babies." "They tell our muscles and bones to get bigger and stronger." "They make hair sprout in unusual places... and sometimes, they really let us down." "Amazing though it seems, hormones will affect our brains too." "They´ll make us think about new things... and we´ll think about them in a new way." "The result for the emerging adult is confusion and defiance." "But eventually, physical, emotional and sexual maturity." "Okay, go ahead." "This programme tells the story... of the human body´s enormous changes during puberty." "But it´s also about what it feels like to experience puberty." "Alright now." "ls that with Doris Day?" "We followed a group of teenage boys in California... and we´ve done something unique." "For a crucial eighteen months of her life... we´ve watched and listened... as a British girl goes through the ups and downs of adolescence." "Now she´s on the threshold of adulthood." "But when we first met, she looked and felt very different." "My name´s Beatrice." "I´m twelve years old." "My birthday´s in November." "My parents are divorced and I live with my mother and stepfather." "My mum´s a councillor and my stepfather is a solicitor." "Sean, shut up." "At twelve years old, Beatrice is a success." "It´s not just that she´s bright and likeable... but in terms of biology she´s done everything a child should do." "She´s survived her most dangerous moment, her birth." "From being a helpless baby she´s gained control." "She´s learnt to walk and to talk... and to cope with the complex social world around her." "Thanks a lot." "But she´s all too aware of what her future has in store." "When you´re a teenager, apparently you go bolshie." "You get your periods, you get pubic hair... you get taller, you get sort of... you get wider at the hips... I think it is I can´t remember... and you get breasts and all this." "And I don´t know I just... I just don´t sort of want it to happen really." "Remembering back to your achievements last year... when you won the..." "was it cross country?" "I´m quite happy with myself the way I am." "And I don´t know... I´m quite happy being a kid." "But however unattractive the prospect of leaving childhood is... in one way Beatrice is very lucky to have had one at all." "Human beings are unique... in the way they linger as children for an extraordinary long time." "If Beatrice were any other animal, she´d have stopped being a kid a long time ago." "Nica is a thirteen week old Bengal tiger." "For her, like most animals, the journey from new-born to fully grown happens as one continuous process... and in just over two years´ time, she´ll be ready to have cubs of her own." "But if humans grew up in the same way, we´d be to have children by the age of four... and would be fully grown by about six." "That´s because we do something very unusual." "We stop the journey from baby to sexual maturity when we´re tiny, just six months old... and though we keep growing, we wait for more than a decade before gearing up to have children." "For Nica´s ancient ancestors, spending ten tiger years without getting ready to have cubs... would have been a dangerous waste of time." "But for our ancestors, things must have been very different." "They needed that time for something so vital to their survival... that even sex could wait, and that something is quite surprising." "It´s learning." "Nought times six is nought." "One times six is six." "Two times six is twelve." "1 Wherever you look in the world... all children have to learn the skills they need for survival." "Not just the obvious ones, like making yourself understood... but the things we don´t think of as learning at all." "Like walking and controlling our bodies." "And as children we can learn faster than we´ll ever be able to again." "Magnified ten thousand times, this is a single human brain cell." "Your brain has a hundred billion of them." "Every one is connected to thousands of others through their tiny branches... and each join adds a little bit more to the intricate picture of who we are." "But as children the connections are still being made." "Like a plant exploring it´s surroundings... brain cells like these are growing their branches... constantly reaching out to each other." "Learn to ride a bike and you wire up a tiny part of the brain." "Learn a new word, or how to catch a bull, and you forge new links." "And with difficult tasks, like writing, it´s only by doing the same thing over and over again... that the connections are made strong." "In the end, they take root and stay with us for the rest of our lives." "But though learning is so vitally important, there comes a time when our bodies have to move on... and the roller coaster of puberty lurches into action." "We don´t know what exactly decides when that should be, but we do know that when it does start it´s the brain that´s in control." "Peering deep inside the head, you can see where it all happens." "Shaded white, it´s the body´s autopilot, a tiny gland that constantly adjusts things like temperature, blood pressure, thirst and hunger." "It´s called the hypothalamus... and it´s the driving force behind puberty." "From it´s position in the centre of the head... it can control parts of the body far away... and it does so with a remarkable trick... by dispatching highly efficient chemicals into the blood." "These chemicals are called hormones... and though you can´t see them in the blood... take them out of the body, and they´re suddenly revealed." "Each one is a uniquely shaped molecule that... like a key in a lock... can fit into specific receptors all over the body." "Each hormone carries a different message." "For example, adrenaline can make us run faster for a moment... while the hormones of puberty change our lives forever." "This system is so finely tuned that... even the tiniest amounts can have dramatic effects." "And at the start of puberty they come out at night." "In the restless nights of early puberty, Beatrice´s brain... dispatches it´s chemical messages every ninety minutes." "And her body listens to the signals carried in her blood." "Not just to the amount of hormones, but to the patterns of their release." "In a boy, it will be the testes that pick up the signals." "In Beatrice, it´s her ovaries." "The ovaries and testes spike the blood with two potent ingredients... oestrogen and testosterone." "Circulating everywhere from head to toe... these are the real heavyweights of puberty." "They make the roller coaster an unpredictable and emotional ride." "Some days you feel like you´re the bomb... everything´s going good in your life, everything´s going to great." "Nothing you can´t expect anything more in your room..." "Others it feels like that you´re nothing like you´ve made mistakes... that it´s over and stuff that you might as well give up... and then it goes back up and then it goes back down." "So, it´s always, it´s always like up and down, lt´s never a straight line or it´s never always inclining up." "It´s always bumpy." "Beatrice too, can´t control the journey she´s on." "Biology has taken over and the hormones inside her have reached critical levels." "Her body is now being rebuilt around her." "I don´t like the physical side of it." "I´d just rather it appeared one morning... but then that would all be a bit awkward but, you know... your upper body begins to..." "You get, you get pubic hairs and that´s a right bit of a bummer." "And then you just get larger in different places... and smaller and whatever..." "Big breaths in and out." "There we go." "Lovely, right." "Let me just swivel round and I´ll sit in." "How old are you now?" "Thirteen." "Thirteen?" "Right." "Can I listen here?" "I haven´t got hips yet but I´m supposed to get hips aren´t l?" "And I don´t know if I want hips or not." "That´s lovely." "Well done." "And just pop it round here." "Have you put much weight on recently?" "No." "No?" "l don´t know, I don´t think so." "One of the remarkable things about puberty is... how different the changes are in boys from girls." "Take this perfectly ordinary family." "There´s a vast and pretty obvious difference... between mum´s and dads´ bodies." "Yet the two children are surprisingly similar." "Christopher and his sister, Kerry are seven and nine." "Until they reach puberty, their chests are biologically identical." "So what makes them change in such different ways?" "It´s those hormones again, which arrive in very different combinations." "Girls bodies are flooded with oestrogen and their chests respond." "Across the world, there´s a huge variety of size and shape... but every woman´s breasts go through the same stages of development." "First the cells which will eventually make milk ducts start dividing." "The dark area around the nipple begins to grow." "Within months the breasts start expanding." "Fat is laid down as the adult shape forms." "It will be around four years before the skin around the nipple lies flat." "Now look inside." "You can see the cause of these radical changes." "A rich pattern of interconnecting tubes and glands has evolved." "It is these and the fat around them that give the breast it´s shape." "It´s painful to run, let me tell you that." "Because what happens up above you have to start wearing a bra." "Sorry, I had to mention it." "It gets really painful to run." "And they, their..." "their bras are really uncomfortable... and it´s just like having this strap put across your chest permanently." "But just getting breasts is not the end of the story." "They will grow again during pregnancy and... only after a woman gives birth will they be fully mature... when in most cases they start producing milk." "While a girl´s body begins to change shape... a less obvious, but more important transition... is taking place deep inside her." "In her ovaries." "The size and shape of a walnut... these two off-white organs rest either side of the pelvis." "Not only do they produce the hormones that drive puberty... but they contain the raw material of new life." "A woman´s eggs." "More than a hundred thousand in each one." "From puberty, once a month, one of these eggs will be set free." "Carried inside the Fallopian tube, it takes the egg three days... to make the fifteen-centimetre journey from ovary to womb." "Meanwhile, the womb prepares for a possible pregnancy." "Its lining thickens, ready to be home for a fertilised egg." "This is it." "Ten thousand times larger than real life." "A strange and dramatic landscape." "A food-rich bed, up to a centimetre thick... its only purpose to nurture new life." "But if the egg is not fertilised, the bed is not needed." "These remarkable pictures reveal the cervix... the opening of the womb." "They show the lining, unused, beginning to flow away." "In her period which follows... the average woman will lose an eggcup-full of blood." "I don´t want to get periods." "I´ll tell you why, because... people tend to get moody." "One of my friends has got her periods and she gets really, really moody," "Really her ´Oh God I hate you´... and then two hours later she´ll be back saying... ´Oh I´m really sorry that I got all cross with you.´" "´Just shut up won´t you?" "´" "And I don´t know, some people get pains... and I don´t know if I will, I hope not... but, you know, it´s a... I don´t like the idea of getting my periods or whatever." "Like it or not, once the roller coaster starts, there´s no stopping it." "With hormones pulsing through her day after day," "Beatrice´s body races ahead out of control." "Yet it can all seem painfully slow." "You know I just wish, I really wish sometimes that it just appeared one morning." "That you went into a little cocoon and I woke up... and it was all there and you were used to it." "Not it happening over three years... or four or five or whatever it is." "One of the things I like everyone used to be taller than me... and now a lot of my friends are still taller than me, but mostly a lot of adults are really short." "So I like being the fact that I´m taller than a lot of people... and being bulky and big too." "Boys´ bodies too are growing faster than at any time since they were toddlers." "It´s easy to develop your body too when you´re like in puberty." "It, when you´re like little when you work out... it doesn´t show up as much." "You start eating a lot." "and then you start getting bigger and stuff and... you feel other stuff you´re getting bigger so you feel kind of manly." "All the changes they experience... are driven by their own sex hormone testosterone... and it´s made in the testes." "As puberty starts, the testes begin to grow." "It´s the first outward sign that anything is actually happening." "The skin of the scrotum gets rougher and there´s a wispy growth of pubic hair." "Inside the testes the tangle of tiny tubes... miniature factories that will soon start to churn out sperm." "And they´ll do it on a massive scale." "A thousand every second." "Shortly after the testes start growing... the penis itself begins to catch up." "The skin gets darker... and in four years the machinery of reproduction is complete." "With a special camera that shows heat as colour... we can see why the testicles are where they are." "he red and yellow of the tummy show it´s hotter... than the bits coloured green and blue." "Sperm factories work best... when slightly cooler than the bulk of a man´s body." "Hanging low keeps them cool." "And it´s now, of course... that the penis starts getting up to some new tricks." "I had one first erection where l didn´t know what it was." "Then I had a first erection where l knew what it was." "I had two." "One that I didn´t know where l was." "That´s the first one." "You´re saying that the first one you didn´t know what it was." "And then the second one you finally knew what it was." "Exactly." "And my... it was like pulsating." "You know ding dong, ding dong, ding dong." "And I was sitting there like I have to use the bathroom." "I really have to piss then because I didn´t know what it was." "And it was all big and blue and well, no it was, it can´t be blue." "And I was sitting there like something´s going to come out... and I´d better go to the bathroom." "Inside, the penis is made of a spongy tissue... filled with thousands of tiny blood vessels." "Normally, blood flows in and out at a constant rate." "But during an erection, blood flow increases dramatically." "Blood vessels at the base of the penis are squeezed." "Blood still flows in, but it can´t get out." "Pressure builds up." "The thermal camera shows the heat produced... by all that extra trapped blood." "And to the horror of it´s owner... the penis seems to have a mind of it´s own." "I don´t like when you get an erection in class." "You´re like sitting there like..." "You´re kind of hiding..." "I try to tuck it under my belt." "I fix it up and just hold it down." "These involuntary stirrings happen... as the body learns to control it´s new functions." "But there´s still one more surprise in store." "There was like in sixth grade... I think I was just like watching TV one night... and I saw this foreign girl and it was like... some movie where there was like this really nice looking girl... I was damn, she looked good and then I just dreamed about her... I woke up in the middle of the night... and something was like wet on pants, on my boxers." "I was like what the hell... I had sex like a little while before that." "So I knew right then I was like okay." "I´m ready to be a man." "I got to clean it up." "Yeah." "And change my boxer." "It didn´t get in my bed though, just my boxes..." "Horrible!" "This is a view inside the sperm ducts." "It´s unlikely that the boy´s first wet dreams contained any sperm at all." "It takes time for the machinery of production to crank up... and the first few times it´s firing blanks." "But even when the system kicks in, most of the fluid isn´t sperm at all." "It´s a liquid which both protects sperm from the acid of a woman´s vagina... and gives them energy for their long swim ahead." "But once the sperm factory is up and running... there´s no going back." "A man will go on producing some sperm for the rest of his life." "Quite apart from the physical transformation they bring... hormones trigger a much wider change." "They influence teenagers´ whole outlook on life." "Like my mum that I, that I wear too much black." "How can you wear too much black?" "I don´t, I never tried that." "I just try on the smallest one." "For Beatrice and her friends, this means experimenting." "Learning to take charge of their lives... trying out attitudes and opinions to see if they fit." "You might as well as just wear a couple of wires, joined up." "They didn´t... at all." "Yeah." "You know it´s basically simply." "I don´t know why they have so much decoration on them." "I mean who´s going to see them?" "Your husband?" "Your...?" "What is it?" "Yeah." "Yeah, I like the top." "Wonderful yeah." "Can I...?" "Oh no." "I quite like that." "I´m sorry but this may seem extremely sad but I like that." "Just as the body is test driving its systems... the brain is beginning to explore its new world." "She´s become, since the summer, significantly more independent." "But still likes to have us around I think in the background." "Just so we´re there, but she´s actually doing her own thing." "So she´s sort of got some safety I suppose." "Okay." "I´m not sure." "What do you think?" "The top, not the skirt...!" "She was very proud of me... because caught the train by myself to Southampton." "And that was a sort of big achievement." "Because she´s quite testing in the sort of questions she asks and her opinion." "She´s got lots and lots of opinions about things... that all come from the outside, or come from school or... that´s all really quite different." "Teenagers, notoriously, want to break free from their parents... and their rebellion can cause pain all round." "Okay?" "Oh, oh dear!" "But children are only doing what´s needed to maintain the next generation." "Learning to become effective parents." "They´re beginning to look after themselves... and recognise the responsibilities of adulthood." "Emotionally, you get down on yourself more as a teenager... when you´re sixteen than I was at eleven." "Usually I didn´t have anything to worry about when I was eleven." "But now I have a lot of stuff to worry about." "I have a lot of things to worry about in like in life and stuff." "Girls, parents, teachers, school." "So that´s a lot of difference." "Usually when I was eleven I had more of people watching me... and always making choices for me or with me." "Now it´s more by myself with a little help and... in the future it´s going to be by myself." "As we´ve seen, many of the changes of puberty are really quite subtile." "But one is blindingly obvious." "We just grow much bigger." "And how we grow is rather surprising... because it´s not always bones that grow." "This scanner produces a magnetic field... ten thousand times greater than the earth´s." "Enough to see right through me." "My hand and wrist are an intricate mesh of tightly packed bones." "But if you could have seen them when I was a child... they would have been very different." "This x-ray study is unique." "And going backwards over twenty years... reveals a remarkable thing." "The hands of children are not all bone." "There for instance, no knuckles... and there, look at the gaps in the wrist." "Instead of bone, there´s cartilage... something the machine can´t see." "Only when cartilage turns into the bone can the hand grow." "How does this happen?" "It´s hormones again." "Puberty pumps them out and joints get bigger and limbs get longer." "By the end of our teens, there is no more cartilage and there can be no more growth." "Boys and girls have two distinct periods of growth." "When we´re children our bodies grow in a more or less constant way." "Boys are generally no taller or stronger than girls." "But at puberty all that changes." "James and Annie are brother and sister." "But James, a year and a half older than Annie... is a good ten centimetres shorter." "A lot of my friends are shorter than me but then again... some of them, a lot of them are the same height as me." "So, I´m not like exceptionally tall... and he´s not tall at all." "He must then grow." "Shut up!" "You look freaky!" "You´ve been that height for about a year." "What makes Annie taller at the moment... is that girls get their growth spurt at the start of puberty... while boys get theirs at the end... which could be as much as three years later." "But James needn´t worry." "Starting late means starting from a taller base... so like most boys he´ll end up bigger than most girls... and that probably includes Annie." "From having very similar body shapes... boys and girls now follow very different paths." "A girl´s shape changes to get ready for bearing children." "The hip bones spread outwards and become flatter." "But more important is what happens to the space in the middle." "It opens, ending four centimetres wider than in men." "Just enough for a baby´s head to squeeze through." "The changes in a boy´s body stem... from his need in times gone by to be physically strong." "The testosterone in his system has dramatic effects." "His heart and lungs get bigger." "With each breath more air travels down his windpipe." "Through a massive tubes it ends here... in the three hundred million air sacs that make up his lungs." "Oxygen passes through the membranes and into his blood." "The more that gets to his muscles, the faster he can run." "At the same time, the mechanical parts of his body are adding to his power." "Here we can see the complex array of muscles and tendons... that holds a joint like the knee together." "Watching them move reveals how impressive the human body is." "The two bones don´t actually touch." "The soft tissue between them allows them to move in a smooth and precise way." "In puberty this whole physical system gets better... as muscles and tendons grow larger and stronger." "But there´s one more thing testosterone does." "Looking across the tongue and down the throat... these are vocal chords." "The whiter bits in the middle make sound... vibrating furiously when air flows past..." "At puberty these grow too." "You can see it from the outside." "Vocal chords get longer, voice chamber bigger... sending a man´s voice almost an octave lower than a woman´s." "But the transition is huge and the brain has to re-learn... all the intricate muscle controls that make our voices work." "It´s like learning a new musical instrument... but sometimes even the brain hits a wrong note." "I hate it when your voice starts getting lower... and you start cracking all the time." "Oh yeah!" "And on the phone you go ´Hello´." "People are like ´what the hell´s wrong with you?" "´ l´ll say something to my mom or something and I... I´ll say it all squeaky and then it turns back and... lt echoes." "Sometimes I..." "I can´t control it." "It´s just like..." "With all those hormones wreaking havoc inside us... the body chooses now to confront us with one of life´s trickiest challenges." "Sex." "And I want you to tell me what is the first thing you think of... when you hear that word sex." "Just shout it out." "Boys and girls." "Nice and louder, we need to shout them out." "Orgasm." "Pregnancy." "Positions." "Diseases." "It´s no accident that teenagers seem to wake up one morning... thinking of nothing but sex." "What else do you think of when you hear the word sex?" "Lust." "Trust." "Trust." "Erection." "When we´re children, sex for the most part passes us by." "But in puberty the amounts of oestrogen and testosterone... pumping through the blood rise month by month." "When they reach a critical level... they seem to effect the central part of our brain." "This is the part responsible for our feelings and our desires." "Sex on the brain, one-track minds, that will be our hormones." "No, it´s a word that I don´t see up here." "What is?" "Love!" "Now why is that always the last thing some people think of... instead of the first thing?" "Good question." "The answer seems to be that teenagers´ physical development... runs ahead of their emotional maturity." "The body has sexual urges that the mind can´t yet deal with." "And while it´s catching up, there´s plenty of scope for turmoil." "You know, there´s a huge difference between what people talk about... when they´re talking big and what it is they truly, really want." "What do you think it is girls really want?" "What do you think it is boys really want?" "is it the stuff that you wrote down?" "Guys shouldn´t be as nervous as some guys are towards girls... because girls in the long run want the same thing." "And so, they should just be more outspoken and..." "Yeah, just come forward and say what they feel... or say what they mean." "I think first of all it´s is, it´s physical." "I think that´s what you notice first." "You´re not going to look inside of a girl and say... ´Oh I want her for what she´s thinking.´" "You´re going to look at her because you like what you see." "I think after you go out with them... for a couple of times and you get to see what they´re really thinking... that´s when you decide that´s the girl you want." "Perhaps it´s one of nature´s little jokes." "Just as we´re really growing up... and the way we look is as important to us as life itself... our body starts playing tricks on us." "Are you going to dance?" "Have a party?" "No sooner have we begun to take an interest in the opposite sex... than we´re hit with strange growths that do nothing at all to help romance." "Zits two, three of them." "They´re a teenager´s worst nightmare and they serve no useful purpose." "The upper body is covered in oil glands." "They´re a left over from our hairy past... when they kept our hair sleek and waterproof." "I hate my spots." "I wish I didn´t have them." "During the hormonal onslaught of puberty, these glands go crazy." "They produce a sudden rush of oil with which our skin can´t cope." "The oil blocks the ducts, trapping bacteria... and provoking those nasty but irresistible spots." "And at puberty something else grows." "The sudden appearance of hair is one of the more visible signs of maturity." "But quite why it sprouts in just a few small patches is something of a mystery." "Bizarrely, the answer is probably sweat." "On most of our body sweat is water based." "It helps to cool us down when we overheat." "But where we have our hair, sweat is different." "It´s thicker and milky." "It contains fat and gives off its own smell... which some people believe makes us attractive to each other." "You smell more..." "like must." "A body odour..." "And your body..." "Body odour is one stage further." "Bacteria love fatty sweat." "If it stays around for long... they´ll happily rot it away with alarming results." "I reckon we should tell her about her body problem." "Oddly, while the rest of our hair varies from person to person... pubic hair is nearly always the same." "Thick-stranded, short and curly." "It´s like a forest." "It´s like a wilderness." "This hair, magnified four hundred times, shows you why." "The hairs themselves aren´t round, but flattened." "They´ve been squeezed by the hair follicle." "So as they grow, they spiral." "But why aren´t pubic hairs much longer?" "They grow for just six months." "So when they die and drop out, they´re still quite short." "If they were like head hairs, they´d grow for seven years and we´d all be in trouble." "It´s a bit irritating sometimes." "Especially when you have to do that first bikini line." "It´s now almost a year since we first filmed Beatrice." "In that time, the hormonal cycles driving her body towards maturity... have been getting stronger." "Now the one change Beatrice has been dreading has arrived." "started my period and it caught me completely off guard." "But I was alright." "She was very matter of fact about it, much more so than I was..." "And, I mean, in fact... she let me know by ringing me at work and she said... ´Mum I´ve got some good news and some bad news´." "The good news was about she´s going to be in a top stream..." "And I said ´What´s the bad news?" "´" "She said:" "´l´ve started my period.´" "She said ´Oh do you want me to come home?" "´" "And then she decided she´d go out and celebrate... but we wouldn´t go out and celebrate we´d just..." "She baked a cake and brought me some chocolate éclairs... which was very nice of her." "But actually quite a lot of people who I know celebrated... when they got their period which just seems a bit strange but they." "She´s sort of ambivalent about it." "I think she´s rather proud in a way to have her periods." "But actually at the time, I felt quite tearful, quite sad about it." "I didn´t talk to her about that... because I felt it really the end of my little girl... even though she´s not little any more or anything." "But it was an absolute:" "this is it now." "The good part of it is I know I´m perfectly sort of normal." "I know I´m a girl, I´m a female." "But then it´s sort of the fact that I get a period... and until I get the menopause it will still be that, you know." "Physically, Beatrice is nearly finished her journey." "But there is more to being an adult than having an adult body." "Boys will soon be men but that means accepting adult responsibility," "Something Olof is finding hard to do." "He´s in trouble with his dad." "He´s desperate to go to a party... but he´s failed to finish his chores and he´s been grounded." "Well I´m... I´ve just been told that I can´t attend the party... under, my brot... my dad´s decision." "He said I can´t go." "We had asked him to do a certain thing and he had not done it... and more so than not doing the task... it was not accepting responsibility for not doing it." "It´s just a party and I..." "This is just a small example of a much bigger part of development." "Learning to use our reasoning to cope with complex situations." "These are four digits you know." "Young children tend to see life in black and white." "Pose them a problem that has no clear right or wrong answer... and they´ll have a very simplistic view." "Take this story for example." "Once upon a time there was a man called George." "His wife was dying." "The chemist had a medicine that could save her life... but the medicine cost a thousand pounds." "George didn´t have a thousand pounds... and however hard he tried he could not find the money." "So he stole the medicine." "Do you think George should have done that?" "No, because he could have gone to the police... they could have arrested him." "And that´s illegal." "It´s illegal." "What, what´s illegal?" "To steal." "Well he has got a right but he has a wrong to it as well." "What´s the right?" "The right is that he did try and ask nicely to get the medicine..." "And the wrong is he stole it." "He shouldn´t have done that." "But it´s bad to steal." "Why is it bad to steal?" "Because he can get into really big trouble." "You wouldn´t like it if somebody stole from you." "Three years on, the certainty has all but gone... and the response is dramatically different." "Was there no other way he could find the money?" "He´d tried everything." "He´d tried everything?" "Then in that case he should have broken into the lab... and got the money for his, or got the medicine for his wife." "What, why do you think he should have done that?" "Because like a life is more important than just like stealing something." "It´s difficult thing." "It´s sort of quite moral subject." "Why is it difficult?" "Because you´re doing wrong... and we´ve always been told not to steal things but he´s stealing." "Yes?" "So..." "So, it´s a problem?" "Yeah." "This ability to make complex moral judgements... to see grey where before there was only black and white... may well come from changes in the brain." "In childhood, the brain is constantly evolving... as slowly an insulating coat grows around the nerves in the brain." "This helps information travel faster." "One theory is that at puberty the front part of the brain... the area responsible for complex reasoning, gets its coating." "It may be this that this helps open the door to mature judgement." "The roller coaster ride is almost over." "Our hormones have done their worst." "Girl has become woman." "Boy has become man." "And if the human body were to make a sound... as it neared the end of this turbulent transition... it would probably be a sigh of relief." "For those living through it, there is also relief." "Having spent the last few years... as passengers on the great ride of puberty... we now regain at least the illusion of control." "There will, of course be fine tuning... and emotional turmoil will probably visit us throughout life..." "But biologically we are at last, the finished article." "We are equipped for adulthood, and ready or not, we face the future." "I don´t mind the physical changes at all because... you know, they were meant to happen anyway, so..." "No, I don´t think I´d want to sort of go round life... looking twelve for the rest of my life." "I don´t think I´d be too happy about that." "So, I suppose I´m glad it´s happened really." "My biggest fear is taking responsibility over myself... because I can´t rely on anbody else.... once I´ve got full responsibility over myself..." "Because it´s my problem and... I can´t always rely on everybody else to take care of me." "I´d stick by my statement that I wish... that you woke up one morning and you were just like an adult... I don´t mind the growing sort of growing in sort of height." "But any other way I just..." "it was a curse really." "It´s the curse of puberty."