Inside The Living Body (2007) Movie Script
adulthood and slowly maturity to old age
Using the latest medical imaging
and 3-D computer graphics,
we embarked
on an extraordinary voyage through the body
This is not just the story of one life
it is the story of all our lives,
told from a unique perspective
depth inside the living body
and a new life was created
A single cell has developed into a fully formed baby
We are about to be born
It is impossible to know exactly what it likes to be born
even though we've all been through it
It's certainly surprising,it's probably painful
What scientists do know
is that at the moment of birth,
we experience a surge of adrenaline
even more intense than during a heart attack
This surge of adrenaline helps us live
It kicks start our lungs into during the first breathe
Our lungs have never breathed before
they are still filled with amniotic fluid
we're in danger of drowning
On top of the kidneys, the adrenal glands
flood the blood stream with adrenaline
muscles we need to breathe, suddenly going to spasm
??????????????????
and we take our first breath
It is the most important breathe of our life
the first of 700 million
air rushes down the trachea
through thousand of branching tubes
into nearly 30 million tiny air sacs, the alveoli
these absorb oxygen into our blood
and draw out the carbon dioxide
we exhale with every breath
Now the umbilical cord,
the physical link between mother and baby, is cut
we, are on our own
a baby's organs must adapt to life outside the womb
It is a challenging and risky time
Our heart, no bigger than walnut
has already being pumping for 8 months
but in the first days of life, there is a problem with it
It has 2 holes, one in the aorta, and one in the heart.
In fact, these holes are not defects,
they are remnant of life before birth
when blood circulated through a system of blood vessels
to the placenta
the holes used to divert most of blood away from our inactive lungs
but now the lung is fully functioning,
they seal up forever
Now the heart is working normally
it pumps blood through the tens of thousands of miles of blood vessels.
our other organs're also coming online too
The liver performs over 500 very jobs,
from generating body heat to processing toxins
The kidneys function is to maintain the balance of water in the body.
Our digestive tract must clear itself out
ready to take its first meal.
our bowel is full of digested amniotic fluid
and dead cells
a sticky green black tarry material , called meconium
It is corrosive stuff
In some babies , meconium can end up in the lungs
and attack the delicate lining
though here in the gut, meconium is harmless
and is flushed out within hours
The first gulp of breast milk accelerate this process
The turmoil of birth might now be over
but the bussiness of adapting to life outside the womb
has only just begun
A newborn baby in a first months of life
This is the time when we start to make sense of world around us.
and began to explore it
infancy is a period of rapid growth
both outside and in
The human body is a miracle of microscopic design
tiny perefectly formed orgams
each made up of billions of perfectly functioning cells
These cells are the building blocks of the body
they make us what we are
inside every cell is the same extraordinary engine
a machine that tells each cell how to grow,
and what function it must perform
it s DNA, and it s unique to every person
DNA is the chemical blue print of who we are
the instructions that create each new person
and sends among the journey of life
DNA not only determines our looks and character
but also sets out the timeline of our lives
it decides when we grow , when we develop, when we age
and even when we die
But our life is also shaped by environment around us
and the people we share it with
Our life outside the womb is still a challenge
Even though our mother keeps us warm
we can't regulate our body temperature
It was 38 degrees in the womb.
Here at home, 18 degrees room temprature
is a shock to the system
The problem is,
the region of the brain we use for temprature control
the hypothalamus, is immature
Our infant brain is under pressure
it is Already making 100 trillion simultaneous calculations every second
our hypothalamus
just can't cope with additional task if keeing us warm as well
right now we're in danger of hypothermia
The infrared camera shows the struggle to keep warm.
we are losing precious body heat
The yellow area show where we lose the most
Luckily, we were born prepared
We have a special layer of tissue that keeps us warm
it s fat
normaly found in hibernating animals
Much more than just a insulating layer
this fat is packed with special cells
which actively generate heat
eventually , most of this fat melts away
as the hypothalamus matures
and takes over the job of temperature control
just days old, we know almost nothing about her world.
Everything we do , we do by instinct
even breast feeding
our mother's milk gives us all the nutrients we need
And we drink half of liter of it every day
it is much more than a ultimate super food
it also protects us from hidden dangers
Outside the womb, there are bacteria everywhere
invisible and potentially deadly
Our ??? skin is under constant attack
There are 10 times more bacteria than human cells
in and on our body
Our immune system is under develop
and we can't fight infections of our cells
amazingly our mother fights them for us
through her milk
The close contact between mother and baby
means she absorbs the same germs they're attacking us
her Mature immune system creates antibodies to kill off these bacteria
Then, in masterpiece of natural design
she passes those antibodies to her baby in breast milk.
until our own immune system develops, she will keep us safe
Breast feeding builds a deep bond between mother and child
a bond that will guide us through infancy,and into the outside world
At this age, even a simple trip to the supermarket
is a sensory overload
It's noisy , bright and smelly
High up inside the nose, the specialised olfactory nerves
???? in the stream of air we breathe
they detect chemicals and send an electrical signal to the brain
Our brain interprets these signals as smells
Our sense of smell is very sensitive
we quickly learn to recognize smells
and can identify our mother with our nose
The strange new world is also very noisy
We're bombarded with hundreds of strange new sounds
sound waves make the eardrum vibrate
On the other side of the eardrum
these tiny bones, the ossicles vibrate in sympathy
They're the smallest three bones in our body
They're so small that can fit on a fingertip
???get any bigger, they stay the size all our life
But without them we would never hear a thing
the ossicles are the air amplifiers
they amplify the volume 22 times
The amplified vibrations enter the inner ear - the cochlea
it's lined with delicate hairs
When vibrations pass through, the hairs vibrate
at the top - low-frequency hairs ,
at the base - fragile hairs to high frequency sounds
Each one 200 times thinner than a hair on our head
Over time, loud noises will damage these hairs
but at this age, they are perfect
our hearing will never be this good again
for eye sight, the story is different
The world is blurred and without color
Our eyes're around the develop
we can't pointerize where we ???
and a imature lenses can not focus
The lens flips the image it receives,
our brains corret the image later
Babies can't yet see in color
because the retina, the screen in the back of the eye,
is also immature
the retina has two types of special cells: rods and cones
They turn light into electrical signals
the ones to detect color, the cones are still developing.
so we see almostly in black and white
From the retina, the signals travel along 2 thick nerves
to the back of brain where we process visual information.
When the image arrives, the real challenge begins
Our immature brain has not yet learned to interpret the data
that's changing fast
by 2 months, we can distinguish colors and shades
At 4 months we can identify facial patterns
and by 8 months , we have 20/20 vision
baby's eyes undergo another amazing change
When we're born, our eyes are blue
but gradually cells of the iris begin making pigments
the iris changes into striking pattern of color
a pattern that is unique to each of us.
We're changing in other ways too
over the first 3 months,
we grow by 25% of our orginal body weight every month
fortunately, that growth rate slows
If it did't ,we would all wiegh a frightening 134 tons by 4th birthday!
around the same as a blue whale
At 8 months, all our sense is working properly
we're begining to explore the world
and the sense we use most - is touch
When we touch something, receptors in our fingertips send
the electrical impulses through sensory nerves in our skin,
upon arms , along the spinal cord and in to the brain
The impulses travel fast, 320 km / hour
Sometimes even this is too slow
the body reacts to painful sensation, like a exteme heat,
by a taking a shortcut
The spinal cord intercepts pain messages
and immediately sends back a reflex response
and we move out away
We have sensory receptors all over our skin
but some areas are more sensitive than others
The hands, face and mouth
there are 9,000 sensory receptors on the tongue alone
this is why, babies use their mouths to explore the world
There is another reason for all our gnawing
our baby teeth are coming through
milk teeth formed deep in the gums while we're still in the womb
Now one by one, they are bursting through
It's painful, but it is progress
at last we can eat solid food
Digestions start in the mouth
The teeth grind up the food
next, special glands, under the tongue , pump out saliva
it Helps break down food
Saliva also lubricates the food
on its 12 hours , 4 meters journey through the gut
it'll Pass from the stomach into the small intestine
and finally the large intestine
waves of contracting muscle keep up food move through out journey
in a process call peristalsis
The contractions are so powerful , we can even eat upside down
This is a unique view of where the food is heading
For the first time,
a new camera shows a high definition view
of the journey through our stomach
Food enters the stomach through a hole at top
The stomach is a bag of muscle
it churns, squashes and squeezes the food into liquid
At the same time, acid breaks down the food
The acid is so corrosive
the stomach continually coats its interior walls with mucus for protection
Without it, stomach ulcers would form
After about an hour, the stomach squeezes the broken down food
through a tiny hole called the pyloric sphincter
The food enters the small intestine
a 3 and half meter coil of tube
This is where we absorb most of nutrients.
First, the pancreas pumps out juice that neutralizes the stomach acid
then bile from the liver breaks down the fat into tiny droplets
Smaller droplets are easily for intestine to adsorb
The interior wall of the small intestine
is lined with million of microscopic projections called villi
These increase the surface area of the gut,
making it easy to absorb nutrients
After an hour and a half,
the small intestine has absorbed most of the nutrients
from the food
What's left, enters the large intestine through this,
the ileocecal sphincter
it's a valve that prevents our food going back
there are few nutrients left to absorb Now
the large intestine's main job is to extract water
What remains is a mixture of waste food , dead cells
and lots of bacteria
these bacteria in the large intestine aren't infection
they produce enzymes that break down complex carbohydrates in our food
carbohydrates we couldn't have ???
Finally, after about 12 hours we expel what remains of the meal
by the age of one, we start to interact with our world
We're more independent from our mothers
and now we can crawl, we begin to explore the world on our own
We can crawl because our bones have got stronger
they need to be, we're getting pretty heavy
at birth, our skeleton is mostly cartilage
the same material, our ears're made of
Cartilage is flexible, it what ables us to squeeze through the birth canal
But after birth, our soft skeleton is a problem
cartilage is too weak to support the growing body
and protect vital organs
so it gradually hardens into bone
Cells called osteoblasts
???? minerals that turn soft cartilage
into hard bone
Some bones also fused together
When we are born, we have gaps between the plates of our skull
These allowed the skull to deform during birth
gradually close until our skull is finally complete
As a skeleton develops, so these desire to get around
We're about to hit one of the major milestones in our life
learning to walk
The key to walking isn't strength
it's balance, and the secret to standing
is hidden deep inside the ears
Behind the ossicles,the bones used for hearing,
there are 3 looping structures
Each loop is about the size of small coin
and oriented in 3 planes
These semicircular canals are part of the ear
but have nothing to do with hearing
they're filled with liquid and they work like a spirit level
they Tell us what's up and what's down
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the hair send data to our brain about how we are oriented
and our direction of movement
they help us balance and stand on two feet
And once we've mastered balance,
we're one step closer to learning to walk
Now there is no limit on where we can go
and what we can do.
From a baby to a toddler
We're about to begin our formative years
A time when we'll put our growing brain
and developing a new system to the test
From infancy to childhood
we're still growing fast
and learning to stand on our own two feet
next is a uniquely huge challenge
learning to speak
Most of us learn to talk by our first birthday
but by 2 years old, we're learning 10 new words a day
This is the Broca's area,
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With it you can create sentences
and communicate complex thoughts
Language is what separates us from other animals
By talking, we can exchange thoughts and ideas
We can teach our children not just by showing, but by telling
As our brain develops, we gain other uniquely human qualities
We're aware of our own identity and individuality
we learn to think for ourselves
We become concsious of ourselves as individual
and We're forming memories that will last a lifetime
human childhood is unique
Few other mammals spend such a huge potion of their lifes preparing for adulthood
to do so would be a costly waste of time
by the equivalent age in their life span, most mamal, like dogs
would already be reproducing
///////////////
a timeline set by our DNA clock
puts a delay on our sexual development
to give us enough time for one thing
learning
it takes well over a decade to learn complex skill we need
to become adult
and evetually parents ourselves.
through our childhood, we're prime to learn
Our brain is a mass of 100 billion nerve cells, called neurons
Between them,they generate enough electricity to keep a light bulb burning for a day
the Neurons communicate using electric impulses
Each impulse is a tiny fraction of a thought and memory
When we hear a new word,
our ears convert the sound into electrical impulses in our brain
The brain can learn,
because the connections between the brain cell,the neurons
aren't permanent
The brain revise itselfs
the Neurons send out tentacles, constantly forming new connections
where they meet is a synapse
Chemicals, called neuro transmitters,
bridge the gap. to allow the impulse to continue the chain
The new connections form a pattern - a new memory
We learn by making new connections between brain cells
and then reinforced them through repetition
The stronger the reinforcement, the more likely the memory'll stick
And when later, someone asks us to recall that memory
the same pattern of brain cells ?????
and we remember the answer
Because the brain grows quickly in childhood
millions of new connections'll be made all the time
making this the prefect time to learn
Learning takes many forms
Not only in class room but also in the world at large
We learn by experience, and sometimes these experiences are unpleasant
because we're programmed to try out new things when we're young
we take risk with our body
Fortunately, ???????
capable of repairing itself when injure
A cut knee, is part of childhood
As soon as skin is broken,
the body's repair mechanisms swing into action
blood capillaries can constrict
to reduce bleeding????????
next, platelets, a type of blood cell,
make the blood in the cut become viscous and clot
Eventually, the clot forms a plug that stops blood leaking out
Our cells multiply at profilic rate
not only to increase their numbers of cells in the body
but also to replace worn out tissue with newer , stronger. bigger versions
It's the same process of cell growth that heals wounds
In fact we're so good at healing in our youth, even the scar disappears
Childhood is also the time when our horizons expand
we Interact with more and more people
But this increased sociabiliy exposes us to an incresed risk of infection
Fortunately, our body has a arsenal of defenses against germs
Eyebrows, eyelashes, ear hairs and nasal hairs catch airborne bacteria
Sweat, tears , mucus wash them off
And skin constantly sheds its top layer of cells
taking bacteria with it
The mouth is especially vulnerable
recent discoveries have shown that pathogens found here are so potent
that if they ended up in vital organ like heart
they can even prove fatal
Fortunately, the body has a secret weapon
saliva contains lysozyme, an enzyme specially develop to destroy bacteria
though tiny, saliva glands create nearly 1.5 liters of saliva
every day
When a pathogen like chicken pox
does break through these external defenses
our immune system must react to prevent serious infection
Thousands of tiny viruses travel through the blood
The virus hijacks a cell
????????????
Then the infected cell ruptures
spreading yet more vireses around the body
The outward signs of chickenpox are rash and high temperature
The fever that comes with the infection is a sign that the body is fighting back
The heat slows down the spread of the disease
viruses don't reproduce so well when it's hot
The immune system kicks into action
White blood cells latched onto the infected cells
and pumping poisonous proteins
it kills the cell, but it kills the viruses too
The crusty skin pustules
they're remnants of the battle between the immune system and the chicken pox
Each one contains cell debrid and thousands of dead viruses
It may be unpleasant
but getting diseases like this when we're young
is vital for our developing immune system
Our body creates "memory molecules" against the viruses antibodies
we use to rely on antibody form our mother's milk
now we make our own
If we catch the same disease when we're older
the antibodies enable our body to recognize the virus instantly
white blood cells wipe it out before it ever takes hold
this makes childhood the ideal time for vaccination
Vaccines are harmless doses of certain types of virus
like rubella, mumps or polio
they prompt the body to create antibodies
just As it would if infected
by the age of 11, childhood is nearly over
and We're about to change like never before
We're on the brink of adulthood
But first,the hormone surge of puberty
Puberty doesn't stick to a schedule
it begins at any time, depending our DNA clock, our lifestyles , even our diet
whether female or male, for all of us , it begins in brain
At the base, the hypothalamus
the same region that controls our body temperature
Puberty starts when the hypothalamus releases the protein
Kisspeptin into the brain.
the Kisspeptin triggers the release of other hormones throughout the body
This stimulates the sex organs to mature
In girls, that means ovulation
For the first time on television
a high definition view of the ovaries
these off white organs
This unique footage from Gold Coast IV fertility Centre
shows some thing incredible
An egg, inside a protective blister of liquid
At ovulation,the blister ruptures
the egg inside will travel down the fallopian tube
?????????
or lost in menstruation
From the onset of puberty, ovulation occurs once a month
But the ovaries begin another equally important role
they start release in hormones into the bloodstream
including estrogens
they Have dramatic and lasting effects
on both emotional and physical develoment
Both boys and girls experience a growth spread
and each day when we look in the mirror,
we see a new face looking back
And the entire body changes beyond recognition
girls become women, boys become man
male brains also release kisspeptin during puberty
the flood of new hormones stimulate the testicles to stop producing sperm
The testicles also generated 10 fold increase in testosterone
the hormone that turns boy into a man
The larynx opens upon to its forward
the vocal cords stretch wider
the longer cords vibrate at a lower pitch
The voice deepens
Testosterone also stimulates the growth of body hair
and doubles muscle mass
These are changes we can see and hear
but we're changing inside too
In the brain ,nerve cells undergo extensive ????
The result is a transformation of our mood and character
Both sexes suffer of torrent of new emotions
and one new emotion ,bigest them all
For the first time, both sex is finding other sex,
attractive
From the inside out , our bodies are overwhelmed with new sensations
our pulse raises, our blood pressures rises
Our lips gorge, our cheeks flash with blood
These're all signals that we desire someone
And sometimes that desire turns out to be mutual
In adolescence, another major life milestone
our first kiss
In the first 2 decades of life
the human body accomplishes something close to miraculous
We're nearly 4 times our orginal height
We're 21 times heavier
we've digested nearly 9 tons of food
our heart has beaten over billion times
and our lungs have drawn 200 million breath
Finally, we're ready, in mind and body ,to become an adult
From "teens" to "twenties
the rapid growth of childhood and puberty
gives way to a new phase of life
adulthood
The 20's are our peak years, both outside and inside
Our body stops growing taller
but it'll never stop changing
trillions of cells make up Our organs and tissues
over time ,these wear out or get damaged
New cells grow and divide to replace old ones
Over time, whole organs are renewed
we get vaguely a brand new body, every 2 years
Some tissues regenerate even faster
That's why we need to come here,for our hair and nails
hairs are made from modified dead skin cells
Each hair grows from a hair follicle embedded in the skin
the Modified cells grow here
then die as new cells push them up????
we grow an incredible 11 km of hair over our whole body every year
Our hair grows, whether we want it to or not
However, other parts of our body
are partially under our control.
choices we make now, like taking exercise
affect us for the rest of our lives
exercise strengthens the heart,
it's the body's hardest working muscle
Exercise also makes our heart muscle more efficient
each contraction pumps more blood
so the heart can beat slower
it's a similar story in the lungs
Exercise stimulates extra capillaries to grow
so we absorb more oxygen with each breath
we Also inhale bigger breath
so every tiny air sack in the lungs gets filled
The surface area of all these sacks is huge
if u lay them all flat, they would cover a tennis court
working out also strengthens our skeleton
exertion puts pressure on the bones
that encourages the bone cells to renew bone fibers
Specialized cells called osteoclasts
eat out way all the damaged bone
other cells - osteoblasts
rebuild it with newer,stronger material
The result, dense, strong bone
At the same time
Our muscles also build
This is a new imaging technique that combines the highest resolution ct-scans
with cutting edge computer power
it's called Volumedic
And it shows how
over 650 skeletal muscle
make up to a thirth of our adult body weight
muscles are made up from bundles of fibers
a good work out rips these fibers apart
When our cells repair the damage afterwards
they add extra material
The muscles grow back bigger and stronger
through choices we made
unfortunately, some choices are less beneficial
Some choices expose us to damage
that even our youthful cells cann't repair
parties are part of life in your twenties
we all know smoke can damage the lungs
But the smoke is not the only hazard here
From the day we were born, our ears have been gradually damaged by loud noise
The problem is deep inside the ear ,past the ossicle bones, inside the cochlea
These fine hairs, the stereocilia, turn sound into nerve impulses
they are very fragile
Loud noise destroys these irreplaceable cells
the hairs that respond to high frequencies, almost affected
possibly because loud, high pitch sounds,
shape their foundations more violently
The effect's still too small to notice
but the frequencies range of our hearing is already shrinking
Another source of damage is - alcohol
though social drinking is very much part of growing up
alcohol is a poison
As we absorb it into our bloodstream
it affects both our organs and our state of mind
afew drinks raise the heart rate and blood pressure
it makes us feel relaxed
we lose our inhibitions and our fine coordination
These sensations are the result of chemical reactions
inside the brain
especially in this region - the cerebellum
the region responsible for the coordination and balance
Alcohol causes a chemical imbalance in the neurons
While some synapses except signals more often, others become blocked
and the more we drink, the more the synapses are affected
Alcohol also fools the brain to thinking we've drunk too much water
it senses the kidneys into overdraft
expelling valuable liquid into the bladder
we may not feel dehydrated now
but the next morning is a different story
After a party, it's the liver that clears up the mess
The liver is the body's biochemical control center
it Performs over 500 functions
One of them's to convert poisons into harmless chemicals
one of the poisons is alcohol
The process demands water
and the liver doesn't care where it takes it from
the brain is 75% water
When the liver demands water, it's the brain that suffers
Water and essential minerals are sucked out and the brain shrinks away from the skull
We experience a very particular kind of headache - a hangover
The best cure - drink some water
Time passes and we get to know our limits
now new challenge is around horizon
It is time to find love and have children of our own
Many of us meet our future partner at work
We may think the attraction is social or physical
but alot of it is biological too
We use our eyes to size up our date
but looks aren't every thing
attraction is also about smell
Inside our nose, the olfactory nerves do more than detect smells
They also detect chemicals we can't smell
pheromones
odorless hormonal messengers we release in our sweat
Pheromones are much more than the body's natural perfume
they carry detailed information about our genetic health
and our ability to resist disease
Our brains detect these signals
and help us choose a partner with the best possible genes
But love - is not just an emotion
It's a bond chemistry!
When we see a partner, we release adrenaline into the blood
our heart pounds, we can't sleep
And then as we get closer and more involved
with our lover, another hormone comes into play
our brain floods with dopamine
The feel-good hormone
As potent as cocaine, it induces euphoria and its addictive. it leaves us on thing more
eventually, after a time together, we start thinking about the final stage of love
commitment, marriage and even kids
Love, both chemical and emotional, wins the ????
It's a relationship we hope a last lifetime
and the process of long-term bonding is chemical too
Sex isn't just about procreation or recreation
It also strengthens the bond between lovers
During orgasm, both partner's pituitary glands flood the bodies with oxytocin
the bonding hormone
It's the very same hormone
that binds us to our mother as new born baby
The more sex we have, the more oxytocin we produce
the stronger the bond between us
Some anthropologists believe oxytocin
could be evolution's way of creating a bond
the strong enough ,to keep parents together
through the trials of parenthood
And the time for parenthood is now
An egg - the largest cell in the human body - ripens
and bursts from the ovary
it begins the same monthly journey , hundreds of others made before it
While ?????? were lost in menstruation
this one's destined to become a baby
the smallest cells in the body
enter the vagina during ejaculation
They have a tough journey front of them
First they must survive the hostile environment of the vagina
it's secretions ??????? to prevent bacterial infection
but they also kill sperm
Most of sperm are killed before they reach the cervix
the Surviving sperms swim on into the uterus and fallopian tubes
Muscular contractions in the walls of the fallopian tube
helps the sperm towards the egg
Only a few hundred make it this far
And only one will succeed in fertilizing the egg
This truely is survival of the fittest
only the most viable sperm with the best DNA
will survive to pass on its genes
so far, there is no sign of what is happened
We're totally unaware that we're about to embark a new chapter in our life
over the next 40 weeks
a single cell will develop into baby
Often the first symptom is morning sickness
No one knows for sure what causes the nausea
but one theory is that it protects the fetus from toxins in food
these could harm its tiny organs during this critical phase of development
Another theory is that nausea is side effect of the mother's immune system
as it weakens to avoid attacking the developing embryo
The fetus is effectively a parasite
It ???? the mother's energies as it draws what it needs from her body
it has its own life support system - the placenta
Here the mother's blood passes nutrients across a membrane
into the fetal blood
Thanks to this constant nourishment
The baby grows over 850 grams in 10 weeks
and the uterus expands up to a 1000 times its normal size, just to hold it
The story of human life continues
form the peak years of early adulthood to the joy of becoming a parent
As our children grow older, so do we
Our body is about to face the next challenge
by this time of life, our body has already peaked
We have been aging for many years
but it is only now, in our 40s, we really notice out changing appearance
Our body is changing and begining to show its age
The cumulative effect of years in the sun causes the first symptom
Our skin is getting wrinkled
since birth, we have been replacing our skin at astonishing rate
We can make up to 40,000 new skin cells every minute
these replace the dead cells with constantly sheding
by 45 , we've created more than 180 kg of dust from old skin cells
Our skin cells are never more than a ?????, even at middle age
wrinkles are not caused by damage to the cells
The problem is the stuff that binds some together - collagen
Ultraviolet radiation in sunlight triggers a molecular chain reaction
which degrades collagen
the fibers get thiner and break
our middle age skin loses its elasticity
become saggy and wrinkly
as we enter our 50s
our body's metabolism may be slowing down
but our lifestyle isn't
We have a growing family
and a demanding career
And this can create another killer
stress
We all recognize the outward signs of stress
sweaty palms,a shortness breath, a dizzy feeling
but the real damage takes place inside our body
When we've stressed
the body instinctively shifts into the fight or flight mood
hormones, adrenaline and cortisol flood from the adrenal glands into the bloodstream
This makes muscles contract
arteries constricts, and heart pump faster , increasing blood pressure
We evolved the fight or flight reflects
to respond to attacks from predators
But we cann't escape our predator
The ????? pressure of being a working parent
and our body has no release
It's the constant triggering of fight or flight
that can be damaging to our body
Stress make cause irreparable harm to our cardiovascular network
speeding up the aging process in blood vessels
the High blood pressure damages cells in the artery walls
they Become stiff and thick
Especially here in the biggest artery - the aorta
arteries with stiff walls
restrict blood flow around the body
our Blood pressure rises, so our heart must work harder
It's a vicious circle
The more stress we exprience
the more we damage our blood vessels
And more damaged of our blood vessels ,
the less able we are to deal with the effects of stress
If stress gets out of control
the heart can become enlarged
as it struggles to force blood
through our narrowing , lessy elastic blood vessel
High blood pressure can also rupture blood vessels in the brain
causing stroke
Most of us learn to manage stress
but for women at 50s
another factor compounds the problem
menopause
During menopause
the ovaries run out of eggs
they Also stop producing the sex hormones
estrogen and progesterone
It's signals the end of women's reproductive life
As the supply of hormones winds down
it upsets the balance in regions of the brain
responsible for mood, sleep and temperature control
when the hypothalamus is turned off course
hot flushes occur, moment when the body can't ????????
it's Not just the brain that affected
bones and muscles tissues also weaken
a woman's bodies spend its whole life getting accustomed to these hormones
no they're gone
and the aging process accelerates
as children leave home
and we retire from work
our body enters a new phase of life
old age has arrived
in 70 years we have grown from a tiny baby to an adult
from child, to parent
to grandparent
the Aging process began several decades ago
Now we are on the ????? of old age
It's the final chapter in the journey of life
When we retire from work, our life style begins to slow
Our body's slowing down too
The outward signs of aging are only part of the story
our senses are affected
We have been losing the sensory hairs we used to hear from our cochlea ,
since birth
Now most of higher-frequency hairs are gone
We're even losing hairs in lower-frequencies
????????????????????????
they're slowly seizing up
These days we struggle to hear
our sight continues to worsen
The lenses in our eyes become stiffer
and even change color
from clear blue to frosty yellow brown
the result of lifetime exposure to ultraviolet light.
most of us're never aware of this change
our brain just works harder to compensate for it
Aging also has a dramatic effect on our skeleton
???????????????????????????????
Bone cells still hard to work , destroying old bone
and replacing it with new bone
But old day ???????? between them
osteoclasts ????? destroying bone faster than osteoblasts can build it
What remains is ??????????????
Our bones slowly crumble
And broken bones become a very real danger
it happens in both sexes
but hormonal changes of menopause
accelerate bone loss faster in women
ageing - is one of the great mysteries of life
Why these our appears change so very much
between the ages of 40 and 70 ?
It is more than wear and tear
it's a process affecting every cell in our body
Every day, cells clone themselfs in the billion
the DNA inside is also copied
as old cells die off
the new ones take that place
The trouble is
this cloning system isn't perfect
Any imprefections in DNA are also replicated
in a lifetime, we make so many copies of our cells,
that even the tiniest errors accumulate with time
It's just like using a photocopier
Copies made from copies
degrading quality
In our face
we have totally replaced the bone every 2 years
since we were born
Our 70 year old face
is 35 copy of our baby's face
The imprefections get exaggerating with each copy
so by the time we reach old age
our face looks very different indeed
Another cause of aging - is in the very air we breathe
We need oxygen to live
But throughout our life
it is slowly poisoning us
inside each of our cells
our Mitochondria are like tiny power plants
combining nutrients with oxygen
they create the energy we need
but just like the power plant
they also produce pollution
In this case the pollutant is a form of oxygen itself
the Oxygen molecules change into unstable forms called free radicals
Over a lifetime, these free radicals
slowly suffocate the mitochondria
and damage our cells
Our cells and DNA become more and more damage
and can't replicate themselfs
Our body can't repair its organs properly
eventually they fail
Death, like life, is an amazing biological process
engineering to the cells of the body
Just as our DNA
????? the timeline of our development
it also puts a cap on how long we can live
Each time a cell copies itself
??????? behind the tiny piece of DNA
After billions of divisions
so much DNA is lost
the cells eventually lose the ability to divide all together
Death is not instantaneous
It is a gradual winding down of tissues and organs
It's thought that the heart's final pump flushes the bloodstream with endorphins
the body's natural pain killer
now starved of oxygen
tissues can not function
within 10 seconds, our brain's electrical activity drops
within 4 minutes, it is damaged irreversibly
our Hearing is the last sense to die
Even after death, some cells're still alive
it can take 24 hours for skin cells to stop dividing
And the amazing 37 hours, before our last brain cell
fires its final impulse
there is a sane, the life goes on
For some of us
it could even go on for some time
Current trends suggest that children born in the West today
can expect to live into the 80 and beyond
and Even after we've gone
we live on through our left ones
Our children and our children's children carry our genes
in every one of their cells
They also carry memories of us too
the moments they have share from our extraordinary story
All journeys must oneday end
and what a journey it has be
Using the latest medical imaging
and 3-D computer graphics,
we embarked
on an extraordinary voyage through the body
This is not just the story of one life
it is the story of all our lives,
told from a unique perspective
depth inside the living body
and a new life was created
A single cell has developed into a fully formed baby
We are about to be born
It is impossible to know exactly what it likes to be born
even though we've all been through it
It's certainly surprising,it's probably painful
What scientists do know
is that at the moment of birth,
we experience a surge of adrenaline
even more intense than during a heart attack
This surge of adrenaline helps us live
It kicks start our lungs into during the first breathe
Our lungs have never breathed before
they are still filled with amniotic fluid
we're in danger of drowning
On top of the kidneys, the adrenal glands
flood the blood stream with adrenaline
muscles we need to breathe, suddenly going to spasm
??????????????????
and we take our first breath
It is the most important breathe of our life
the first of 700 million
air rushes down the trachea
through thousand of branching tubes
into nearly 30 million tiny air sacs, the alveoli
these absorb oxygen into our blood
and draw out the carbon dioxide
we exhale with every breath
Now the umbilical cord,
the physical link between mother and baby, is cut
we, are on our own
a baby's organs must adapt to life outside the womb
It is a challenging and risky time
Our heart, no bigger than walnut
has already being pumping for 8 months
but in the first days of life, there is a problem with it
It has 2 holes, one in the aorta, and one in the heart.
In fact, these holes are not defects,
they are remnant of life before birth
when blood circulated through a system of blood vessels
to the placenta
the holes used to divert most of blood away from our inactive lungs
but now the lung is fully functioning,
they seal up forever
Now the heart is working normally
it pumps blood through the tens of thousands of miles of blood vessels.
our other organs're also coming online too
The liver performs over 500 very jobs,
from generating body heat to processing toxins
The kidneys function is to maintain the balance of water in the body.
Our digestive tract must clear itself out
ready to take its first meal.
our bowel is full of digested amniotic fluid
and dead cells
a sticky green black tarry material , called meconium
It is corrosive stuff
In some babies , meconium can end up in the lungs
and attack the delicate lining
though here in the gut, meconium is harmless
and is flushed out within hours
The first gulp of breast milk accelerate this process
The turmoil of birth might now be over
but the bussiness of adapting to life outside the womb
has only just begun
A newborn baby in a first months of life
This is the time when we start to make sense of world around us.
and began to explore it
infancy is a period of rapid growth
both outside and in
The human body is a miracle of microscopic design
tiny perefectly formed orgams
each made up of billions of perfectly functioning cells
These cells are the building blocks of the body
they make us what we are
inside every cell is the same extraordinary engine
a machine that tells each cell how to grow,
and what function it must perform
it s DNA, and it s unique to every person
DNA is the chemical blue print of who we are
the instructions that create each new person
and sends among the journey of life
DNA not only determines our looks and character
but also sets out the timeline of our lives
it decides when we grow , when we develop, when we age
and even when we die
But our life is also shaped by environment around us
and the people we share it with
Our life outside the womb is still a challenge
Even though our mother keeps us warm
we can't regulate our body temperature
It was 38 degrees in the womb.
Here at home, 18 degrees room temprature
is a shock to the system
The problem is,
the region of the brain we use for temprature control
the hypothalamus, is immature
Our infant brain is under pressure
it is Already making 100 trillion simultaneous calculations every second
our hypothalamus
just can't cope with additional task if keeing us warm as well
right now we're in danger of hypothermia
The infrared camera shows the struggle to keep warm.
we are losing precious body heat
The yellow area show where we lose the most
Luckily, we were born prepared
We have a special layer of tissue that keeps us warm
it s fat
normaly found in hibernating animals
Much more than just a insulating layer
this fat is packed with special cells
which actively generate heat
eventually , most of this fat melts away
as the hypothalamus matures
and takes over the job of temperature control
just days old, we know almost nothing about her world.
Everything we do , we do by instinct
even breast feeding
our mother's milk gives us all the nutrients we need
And we drink half of liter of it every day
it is much more than a ultimate super food
it also protects us from hidden dangers
Outside the womb, there are bacteria everywhere
invisible and potentially deadly
Our ??? skin is under constant attack
There are 10 times more bacteria than human cells
in and on our body
Our immune system is under develop
and we can't fight infections of our cells
amazingly our mother fights them for us
through her milk
The close contact between mother and baby
means she absorbs the same germs they're attacking us
her Mature immune system creates antibodies to kill off these bacteria
Then, in masterpiece of natural design
she passes those antibodies to her baby in breast milk.
until our own immune system develops, she will keep us safe
Breast feeding builds a deep bond between mother and child
a bond that will guide us through infancy,and into the outside world
At this age, even a simple trip to the supermarket
is a sensory overload
It's noisy , bright and smelly
High up inside the nose, the specialised olfactory nerves
???? in the stream of air we breathe
they detect chemicals and send an electrical signal to the brain
Our brain interprets these signals as smells
Our sense of smell is very sensitive
we quickly learn to recognize smells
and can identify our mother with our nose
The strange new world is also very noisy
We're bombarded with hundreds of strange new sounds
sound waves make the eardrum vibrate
On the other side of the eardrum
these tiny bones, the ossicles vibrate in sympathy
They're the smallest three bones in our body
They're so small that can fit on a fingertip
???get any bigger, they stay the size all our life
But without them we would never hear a thing
the ossicles are the air amplifiers
they amplify the volume 22 times
The amplified vibrations enter the inner ear - the cochlea
it's lined with delicate hairs
When vibrations pass through, the hairs vibrate
at the top - low-frequency hairs ,
at the base - fragile hairs to high frequency sounds
Each one 200 times thinner than a hair on our head
Over time, loud noises will damage these hairs
but at this age, they are perfect
our hearing will never be this good again
for eye sight, the story is different
The world is blurred and without color
Our eyes're around the develop
we can't pointerize where we ???
and a imature lenses can not focus
The lens flips the image it receives,
our brains corret the image later
Babies can't yet see in color
because the retina, the screen in the back of the eye,
is also immature
the retina has two types of special cells: rods and cones
They turn light into electrical signals
the ones to detect color, the cones are still developing.
so we see almostly in black and white
From the retina, the signals travel along 2 thick nerves
to the back of brain where we process visual information.
When the image arrives, the real challenge begins
Our immature brain has not yet learned to interpret the data
that's changing fast
by 2 months, we can distinguish colors and shades
At 4 months we can identify facial patterns
and by 8 months , we have 20/20 vision
baby's eyes undergo another amazing change
When we're born, our eyes are blue
but gradually cells of the iris begin making pigments
the iris changes into striking pattern of color
a pattern that is unique to each of us.
We're changing in other ways too
over the first 3 months,
we grow by 25% of our orginal body weight every month
fortunately, that growth rate slows
If it did't ,we would all wiegh a frightening 134 tons by 4th birthday!
around the same as a blue whale
At 8 months, all our sense is working properly
we're begining to explore the world
and the sense we use most - is touch
When we touch something, receptors in our fingertips send
the electrical impulses through sensory nerves in our skin,
upon arms , along the spinal cord and in to the brain
The impulses travel fast, 320 km / hour
Sometimes even this is too slow
the body reacts to painful sensation, like a exteme heat,
by a taking a shortcut
The spinal cord intercepts pain messages
and immediately sends back a reflex response
and we move out away
We have sensory receptors all over our skin
but some areas are more sensitive than others
The hands, face and mouth
there are 9,000 sensory receptors on the tongue alone
this is why, babies use their mouths to explore the world
There is another reason for all our gnawing
our baby teeth are coming through
milk teeth formed deep in the gums while we're still in the womb
Now one by one, they are bursting through
It's painful, but it is progress
at last we can eat solid food
Digestions start in the mouth
The teeth grind up the food
next, special glands, under the tongue , pump out saliva
it Helps break down food
Saliva also lubricates the food
on its 12 hours , 4 meters journey through the gut
it'll Pass from the stomach into the small intestine
and finally the large intestine
waves of contracting muscle keep up food move through out journey
in a process call peristalsis
The contractions are so powerful , we can even eat upside down
This is a unique view of where the food is heading
For the first time,
a new camera shows a high definition view
of the journey through our stomach
Food enters the stomach through a hole at top
The stomach is a bag of muscle
it churns, squashes and squeezes the food into liquid
At the same time, acid breaks down the food
The acid is so corrosive
the stomach continually coats its interior walls with mucus for protection
Without it, stomach ulcers would form
After about an hour, the stomach squeezes the broken down food
through a tiny hole called the pyloric sphincter
The food enters the small intestine
a 3 and half meter coil of tube
This is where we absorb most of nutrients.
First, the pancreas pumps out juice that neutralizes the stomach acid
then bile from the liver breaks down the fat into tiny droplets
Smaller droplets are easily for intestine to adsorb
The interior wall of the small intestine
is lined with million of microscopic projections called villi
These increase the surface area of the gut,
making it easy to absorb nutrients
After an hour and a half,
the small intestine has absorbed most of the nutrients
from the food
What's left, enters the large intestine through this,
the ileocecal sphincter
it's a valve that prevents our food going back
there are few nutrients left to absorb Now
the large intestine's main job is to extract water
What remains is a mixture of waste food , dead cells
and lots of bacteria
these bacteria in the large intestine aren't infection
they produce enzymes that break down complex carbohydrates in our food
carbohydrates we couldn't have ???
Finally, after about 12 hours we expel what remains of the meal
by the age of one, we start to interact with our world
We're more independent from our mothers
and now we can crawl, we begin to explore the world on our own
We can crawl because our bones have got stronger
they need to be, we're getting pretty heavy
at birth, our skeleton is mostly cartilage
the same material, our ears're made of
Cartilage is flexible, it what ables us to squeeze through the birth canal
But after birth, our soft skeleton is a problem
cartilage is too weak to support the growing body
and protect vital organs
so it gradually hardens into bone
Cells called osteoblasts
???? minerals that turn soft cartilage
into hard bone
Some bones also fused together
When we are born, we have gaps between the plates of our skull
These allowed the skull to deform during birth
gradually close until our skull is finally complete
As a skeleton develops, so these desire to get around
We're about to hit one of the major milestones in our life
learning to walk
The key to walking isn't strength
it's balance, and the secret to standing
is hidden deep inside the ears
Behind the ossicles,the bones used for hearing,
there are 3 looping structures
Each loop is about the size of small coin
and oriented in 3 planes
These semicircular canals are part of the ear
but have nothing to do with hearing
they're filled with liquid and they work like a spirit level
they Tell us what's up and what's down
///////////////////////////
the hair send data to our brain about how we are oriented
and our direction of movement
they help us balance and stand on two feet
And once we've mastered balance,
we're one step closer to learning to walk
Now there is no limit on where we can go
and what we can do.
From a baby to a toddler
We're about to begin our formative years
A time when we'll put our growing brain
and developing a new system to the test
From infancy to childhood
we're still growing fast
and learning to stand on our own two feet
next is a uniquely huge challenge
learning to speak
Most of us learn to talk by our first birthday
but by 2 years old, we're learning 10 new words a day
This is the Broca's area,
///////////////////////
With it you can create sentences
and communicate complex thoughts
Language is what separates us from other animals
By talking, we can exchange thoughts and ideas
We can teach our children not just by showing, but by telling
As our brain develops, we gain other uniquely human qualities
We're aware of our own identity and individuality
we learn to think for ourselves
We become concsious of ourselves as individual
and We're forming memories that will last a lifetime
human childhood is unique
Few other mammals spend such a huge potion of their lifes preparing for adulthood
to do so would be a costly waste of time
by the equivalent age in their life span, most mamal, like dogs
would already be reproducing
///////////////
a timeline set by our DNA clock
puts a delay on our sexual development
to give us enough time for one thing
learning
it takes well over a decade to learn complex skill we need
to become adult
and evetually parents ourselves.
through our childhood, we're prime to learn
Our brain is a mass of 100 billion nerve cells, called neurons
Between them,they generate enough electricity to keep a light bulb burning for a day
the Neurons communicate using electric impulses
Each impulse is a tiny fraction of a thought and memory
When we hear a new word,
our ears convert the sound into electrical impulses in our brain
The brain can learn,
because the connections between the brain cell,the neurons
aren't permanent
The brain revise itselfs
the Neurons send out tentacles, constantly forming new connections
where they meet is a synapse
Chemicals, called neuro transmitters,
bridge the gap. to allow the impulse to continue the chain
The new connections form a pattern - a new memory
We learn by making new connections between brain cells
and then reinforced them through repetition
The stronger the reinforcement, the more likely the memory'll stick
And when later, someone asks us to recall that memory
the same pattern of brain cells ?????
and we remember the answer
Because the brain grows quickly in childhood
millions of new connections'll be made all the time
making this the prefect time to learn
Learning takes many forms
Not only in class room but also in the world at large
We learn by experience, and sometimes these experiences are unpleasant
because we're programmed to try out new things when we're young
we take risk with our body
Fortunately, ???????
capable of repairing itself when injure
A cut knee, is part of childhood
As soon as skin is broken,
the body's repair mechanisms swing into action
blood capillaries can constrict
to reduce bleeding????????
next, platelets, a type of blood cell,
make the blood in the cut become viscous and clot
Eventually, the clot forms a plug that stops blood leaking out
Our cells multiply at profilic rate
not only to increase their numbers of cells in the body
but also to replace worn out tissue with newer , stronger. bigger versions
It's the same process of cell growth that heals wounds
In fact we're so good at healing in our youth, even the scar disappears
Childhood is also the time when our horizons expand
we Interact with more and more people
But this increased sociabiliy exposes us to an incresed risk of infection
Fortunately, our body has a arsenal of defenses against germs
Eyebrows, eyelashes, ear hairs and nasal hairs catch airborne bacteria
Sweat, tears , mucus wash them off
And skin constantly sheds its top layer of cells
taking bacteria with it
The mouth is especially vulnerable
recent discoveries have shown that pathogens found here are so potent
that if they ended up in vital organ like heart
they can even prove fatal
Fortunately, the body has a secret weapon
saliva contains lysozyme, an enzyme specially develop to destroy bacteria
though tiny, saliva glands create nearly 1.5 liters of saliva
every day
When a pathogen like chicken pox
does break through these external defenses
our immune system must react to prevent serious infection
Thousands of tiny viruses travel through the blood
The virus hijacks a cell
????????????
Then the infected cell ruptures
spreading yet more vireses around the body
The outward signs of chickenpox are rash and high temperature
The fever that comes with the infection is a sign that the body is fighting back
The heat slows down the spread of the disease
viruses don't reproduce so well when it's hot
The immune system kicks into action
White blood cells latched onto the infected cells
and pumping poisonous proteins
it kills the cell, but it kills the viruses too
The crusty skin pustules
they're remnants of the battle between the immune system and the chicken pox
Each one contains cell debrid and thousands of dead viruses
It may be unpleasant
but getting diseases like this when we're young
is vital for our developing immune system
Our body creates "memory molecules" against the viruses antibodies
we use to rely on antibody form our mother's milk
now we make our own
If we catch the same disease when we're older
the antibodies enable our body to recognize the virus instantly
white blood cells wipe it out before it ever takes hold
this makes childhood the ideal time for vaccination
Vaccines are harmless doses of certain types of virus
like rubella, mumps or polio
they prompt the body to create antibodies
just As it would if infected
by the age of 11, childhood is nearly over
and We're about to change like never before
We're on the brink of adulthood
But first,the hormone surge of puberty
Puberty doesn't stick to a schedule
it begins at any time, depending our DNA clock, our lifestyles , even our diet
whether female or male, for all of us , it begins in brain
At the base, the hypothalamus
the same region that controls our body temperature
Puberty starts when the hypothalamus releases the protein
Kisspeptin into the brain.
the Kisspeptin triggers the release of other hormones throughout the body
This stimulates the sex organs to mature
In girls, that means ovulation
For the first time on television
a high definition view of the ovaries
these off white organs
This unique footage from Gold Coast IV fertility Centre
shows some thing incredible
An egg, inside a protective blister of liquid
At ovulation,the blister ruptures
the egg inside will travel down the fallopian tube
?????????
or lost in menstruation
From the onset of puberty, ovulation occurs once a month
But the ovaries begin another equally important role
they start release in hormones into the bloodstream
including estrogens
they Have dramatic and lasting effects
on both emotional and physical develoment
Both boys and girls experience a growth spread
and each day when we look in the mirror,
we see a new face looking back
And the entire body changes beyond recognition
girls become women, boys become man
male brains also release kisspeptin during puberty
the flood of new hormones stimulate the testicles to stop producing sperm
The testicles also generated 10 fold increase in testosterone
the hormone that turns boy into a man
The larynx opens upon to its forward
the vocal cords stretch wider
the longer cords vibrate at a lower pitch
The voice deepens
Testosterone also stimulates the growth of body hair
and doubles muscle mass
These are changes we can see and hear
but we're changing inside too
In the brain ,nerve cells undergo extensive ????
The result is a transformation of our mood and character
Both sexes suffer of torrent of new emotions
and one new emotion ,bigest them all
For the first time, both sex is finding other sex,
attractive
From the inside out , our bodies are overwhelmed with new sensations
our pulse raises, our blood pressures rises
Our lips gorge, our cheeks flash with blood
These're all signals that we desire someone
And sometimes that desire turns out to be mutual
In adolescence, another major life milestone
our first kiss
In the first 2 decades of life
the human body accomplishes something close to miraculous
We're nearly 4 times our orginal height
We're 21 times heavier
we've digested nearly 9 tons of food
our heart has beaten over billion times
and our lungs have drawn 200 million breath
Finally, we're ready, in mind and body ,to become an adult
From "teens" to "twenties
the rapid growth of childhood and puberty
gives way to a new phase of life
adulthood
The 20's are our peak years, both outside and inside
Our body stops growing taller
but it'll never stop changing
trillions of cells make up Our organs and tissues
over time ,these wear out or get damaged
New cells grow and divide to replace old ones
Over time, whole organs are renewed
we get vaguely a brand new body, every 2 years
Some tissues regenerate even faster
That's why we need to come here,for our hair and nails
hairs are made from modified dead skin cells
Each hair grows from a hair follicle embedded in the skin
the Modified cells grow here
then die as new cells push them up????
we grow an incredible 11 km of hair over our whole body every year
Our hair grows, whether we want it to or not
However, other parts of our body
are partially under our control.
choices we make now, like taking exercise
affect us for the rest of our lives
exercise strengthens the heart,
it's the body's hardest working muscle
Exercise also makes our heart muscle more efficient
each contraction pumps more blood
so the heart can beat slower
it's a similar story in the lungs
Exercise stimulates extra capillaries to grow
so we absorb more oxygen with each breath
we Also inhale bigger breath
so every tiny air sack in the lungs gets filled
The surface area of all these sacks is huge
if u lay them all flat, they would cover a tennis court
working out also strengthens our skeleton
exertion puts pressure on the bones
that encourages the bone cells to renew bone fibers
Specialized cells called osteoclasts
eat out way all the damaged bone
other cells - osteoblasts
rebuild it with newer,stronger material
The result, dense, strong bone
At the same time
Our muscles also build
This is a new imaging technique that combines the highest resolution ct-scans
with cutting edge computer power
it's called Volumedic
And it shows how
over 650 skeletal muscle
make up to a thirth of our adult body weight
muscles are made up from bundles of fibers
a good work out rips these fibers apart
When our cells repair the damage afterwards
they add extra material
The muscles grow back bigger and stronger
through choices we made
unfortunately, some choices are less beneficial
Some choices expose us to damage
that even our youthful cells cann't repair
parties are part of life in your twenties
we all know smoke can damage the lungs
But the smoke is not the only hazard here
From the day we were born, our ears have been gradually damaged by loud noise
The problem is deep inside the ear ,past the ossicle bones, inside the cochlea
These fine hairs, the stereocilia, turn sound into nerve impulses
they are very fragile
Loud noise destroys these irreplaceable cells
the hairs that respond to high frequencies, almost affected
possibly because loud, high pitch sounds,
shape their foundations more violently
The effect's still too small to notice
but the frequencies range of our hearing is already shrinking
Another source of damage is - alcohol
though social drinking is very much part of growing up
alcohol is a poison
As we absorb it into our bloodstream
it affects both our organs and our state of mind
afew drinks raise the heart rate and blood pressure
it makes us feel relaxed
we lose our inhibitions and our fine coordination
These sensations are the result of chemical reactions
inside the brain
especially in this region - the cerebellum
the region responsible for the coordination and balance
Alcohol causes a chemical imbalance in the neurons
While some synapses except signals more often, others become blocked
and the more we drink, the more the synapses are affected
Alcohol also fools the brain to thinking we've drunk too much water
it senses the kidneys into overdraft
expelling valuable liquid into the bladder
we may not feel dehydrated now
but the next morning is a different story
After a party, it's the liver that clears up the mess
The liver is the body's biochemical control center
it Performs over 500 functions
One of them's to convert poisons into harmless chemicals
one of the poisons is alcohol
The process demands water
and the liver doesn't care where it takes it from
the brain is 75% water
When the liver demands water, it's the brain that suffers
Water and essential minerals are sucked out and the brain shrinks away from the skull
We experience a very particular kind of headache - a hangover
The best cure - drink some water
Time passes and we get to know our limits
now new challenge is around horizon
It is time to find love and have children of our own
Many of us meet our future partner at work
We may think the attraction is social or physical
but alot of it is biological too
We use our eyes to size up our date
but looks aren't every thing
attraction is also about smell
Inside our nose, the olfactory nerves do more than detect smells
They also detect chemicals we can't smell
pheromones
odorless hormonal messengers we release in our sweat
Pheromones are much more than the body's natural perfume
they carry detailed information about our genetic health
and our ability to resist disease
Our brains detect these signals
and help us choose a partner with the best possible genes
But love - is not just an emotion
It's a bond chemistry!
When we see a partner, we release adrenaline into the blood
our heart pounds, we can't sleep
And then as we get closer and more involved
with our lover, another hormone comes into play
our brain floods with dopamine
The feel-good hormone
As potent as cocaine, it induces euphoria and its addictive. it leaves us on thing more
eventually, after a time together, we start thinking about the final stage of love
commitment, marriage and even kids
Love, both chemical and emotional, wins the ????
It's a relationship we hope a last lifetime
and the process of long-term bonding is chemical too
Sex isn't just about procreation or recreation
It also strengthens the bond between lovers
During orgasm, both partner's pituitary glands flood the bodies with oxytocin
the bonding hormone
It's the very same hormone
that binds us to our mother as new born baby
The more sex we have, the more oxytocin we produce
the stronger the bond between us
Some anthropologists believe oxytocin
could be evolution's way of creating a bond
the strong enough ,to keep parents together
through the trials of parenthood
And the time for parenthood is now
An egg - the largest cell in the human body - ripens
and bursts from the ovary
it begins the same monthly journey , hundreds of others made before it
While ?????? were lost in menstruation
this one's destined to become a baby
the smallest cells in the body
enter the vagina during ejaculation
They have a tough journey front of them
First they must survive the hostile environment of the vagina
it's secretions ??????? to prevent bacterial infection
but they also kill sperm
Most of sperm are killed before they reach the cervix
the Surviving sperms swim on into the uterus and fallopian tubes
Muscular contractions in the walls of the fallopian tube
helps the sperm towards the egg
Only a few hundred make it this far
And only one will succeed in fertilizing the egg
This truely is survival of the fittest
only the most viable sperm with the best DNA
will survive to pass on its genes
so far, there is no sign of what is happened
We're totally unaware that we're about to embark a new chapter in our life
over the next 40 weeks
a single cell will develop into baby
Often the first symptom is morning sickness
No one knows for sure what causes the nausea
but one theory is that it protects the fetus from toxins in food
these could harm its tiny organs during this critical phase of development
Another theory is that nausea is side effect of the mother's immune system
as it weakens to avoid attacking the developing embryo
The fetus is effectively a parasite
It ???? the mother's energies as it draws what it needs from her body
it has its own life support system - the placenta
Here the mother's blood passes nutrients across a membrane
into the fetal blood
Thanks to this constant nourishment
The baby grows over 850 grams in 10 weeks
and the uterus expands up to a 1000 times its normal size, just to hold it
The story of human life continues
form the peak years of early adulthood to the joy of becoming a parent
As our children grow older, so do we
Our body is about to face the next challenge
by this time of life, our body has already peaked
We have been aging for many years
but it is only now, in our 40s, we really notice out changing appearance
Our body is changing and begining to show its age
The cumulative effect of years in the sun causes the first symptom
Our skin is getting wrinkled
since birth, we have been replacing our skin at astonishing rate
We can make up to 40,000 new skin cells every minute
these replace the dead cells with constantly sheding
by 45 , we've created more than 180 kg of dust from old skin cells
Our skin cells are never more than a ?????, even at middle age
wrinkles are not caused by damage to the cells
The problem is the stuff that binds some together - collagen
Ultraviolet radiation in sunlight triggers a molecular chain reaction
which degrades collagen
the fibers get thiner and break
our middle age skin loses its elasticity
become saggy and wrinkly
as we enter our 50s
our body's metabolism may be slowing down
but our lifestyle isn't
We have a growing family
and a demanding career
And this can create another killer
stress
We all recognize the outward signs of stress
sweaty palms,a shortness breath, a dizzy feeling
but the real damage takes place inside our body
When we've stressed
the body instinctively shifts into the fight or flight mood
hormones, adrenaline and cortisol flood from the adrenal glands into the bloodstream
This makes muscles contract
arteries constricts, and heart pump faster , increasing blood pressure
We evolved the fight or flight reflects
to respond to attacks from predators
But we cann't escape our predator
The ????? pressure of being a working parent
and our body has no release
It's the constant triggering of fight or flight
that can be damaging to our body
Stress make cause irreparable harm to our cardiovascular network
speeding up the aging process in blood vessels
the High blood pressure damages cells in the artery walls
they Become stiff and thick
Especially here in the biggest artery - the aorta
arteries with stiff walls
restrict blood flow around the body
our Blood pressure rises, so our heart must work harder
It's a vicious circle
The more stress we exprience
the more we damage our blood vessels
And more damaged of our blood vessels ,
the less able we are to deal with the effects of stress
If stress gets out of control
the heart can become enlarged
as it struggles to force blood
through our narrowing , lessy elastic blood vessel
High blood pressure can also rupture blood vessels in the brain
causing stroke
Most of us learn to manage stress
but for women at 50s
another factor compounds the problem
menopause
During menopause
the ovaries run out of eggs
they Also stop producing the sex hormones
estrogen and progesterone
It's signals the end of women's reproductive life
As the supply of hormones winds down
it upsets the balance in regions of the brain
responsible for mood, sleep and temperature control
when the hypothalamus is turned off course
hot flushes occur, moment when the body can't ????????
it's Not just the brain that affected
bones and muscles tissues also weaken
a woman's bodies spend its whole life getting accustomed to these hormones
no they're gone
and the aging process accelerates
as children leave home
and we retire from work
our body enters a new phase of life
old age has arrived
in 70 years we have grown from a tiny baby to an adult
from child, to parent
to grandparent
the Aging process began several decades ago
Now we are on the ????? of old age
It's the final chapter in the journey of life
When we retire from work, our life style begins to slow
Our body's slowing down too
The outward signs of aging are only part of the story
our senses are affected
We have been losing the sensory hairs we used to hear from our cochlea ,
since birth
Now most of higher-frequency hairs are gone
We're even losing hairs in lower-frequencies
????????????????????????
they're slowly seizing up
These days we struggle to hear
our sight continues to worsen
The lenses in our eyes become stiffer
and even change color
from clear blue to frosty yellow brown
the result of lifetime exposure to ultraviolet light.
most of us're never aware of this change
our brain just works harder to compensate for it
Aging also has a dramatic effect on our skeleton
???????????????????????????????
Bone cells still hard to work , destroying old bone
and replacing it with new bone
But old day ???????? between them
osteoclasts ????? destroying bone faster than osteoblasts can build it
What remains is ??????????????
Our bones slowly crumble
And broken bones become a very real danger
it happens in both sexes
but hormonal changes of menopause
accelerate bone loss faster in women
ageing - is one of the great mysteries of life
Why these our appears change so very much
between the ages of 40 and 70 ?
It is more than wear and tear
it's a process affecting every cell in our body
Every day, cells clone themselfs in the billion
the DNA inside is also copied
as old cells die off
the new ones take that place
The trouble is
this cloning system isn't perfect
Any imprefections in DNA are also replicated
in a lifetime, we make so many copies of our cells,
that even the tiniest errors accumulate with time
It's just like using a photocopier
Copies made from copies
degrading quality
In our face
we have totally replaced the bone every 2 years
since we were born
Our 70 year old face
is 35 copy of our baby's face
The imprefections get exaggerating with each copy
so by the time we reach old age
our face looks very different indeed
Another cause of aging - is in the very air we breathe
We need oxygen to live
But throughout our life
it is slowly poisoning us
inside each of our cells
our Mitochondria are like tiny power plants
combining nutrients with oxygen
they create the energy we need
but just like the power plant
they also produce pollution
In this case the pollutant is a form of oxygen itself
the Oxygen molecules change into unstable forms called free radicals
Over a lifetime, these free radicals
slowly suffocate the mitochondria
and damage our cells
Our cells and DNA become more and more damage
and can't replicate themselfs
Our body can't repair its organs properly
eventually they fail
Death, like life, is an amazing biological process
engineering to the cells of the body
Just as our DNA
????? the timeline of our development
it also puts a cap on how long we can live
Each time a cell copies itself
??????? behind the tiny piece of DNA
After billions of divisions
so much DNA is lost
the cells eventually lose the ability to divide all together
Death is not instantaneous
It is a gradual winding down of tissues and organs
It's thought that the heart's final pump flushes the bloodstream with endorphins
the body's natural pain killer
now starved of oxygen
tissues can not function
within 10 seconds, our brain's electrical activity drops
within 4 minutes, it is damaged irreversibly
our Hearing is the last sense to die
Even after death, some cells're still alive
it can take 24 hours for skin cells to stop dividing
And the amazing 37 hours, before our last brain cell
fires its final impulse
there is a sane, the life goes on
For some of us
it could even go on for some time
Current trends suggest that children born in the West today
can expect to live into the 80 and beyond
and Even after we've gone
we live on through our left ones
Our children and our children's children carry our genes
in every one of their cells
They also carry memories of us too
the moments they have share from our extraordinary story
All journeys must oneday end
and what a journey it has be