This athlete is a champion
of one of the world's most spectacular sports,
bull jumping.
This boxer survives being hit by a fist,
traveling with a force of a third of a ton.
And this man is hoping that surgeons
will replace his damaged limbs
with another man's hands.
Can we Twitter that the surgery has started?
Their stories are part of your story.
The story of what makes you human.
Hidden deep beneath your skin,
is an extraordinary universe,
where billions of tiny powerhouses generate energy,
where vast forests digest food.
Where the tiniest movements set off
violent chain reactions.
This is a fantastic voyage
through the most complex organism on earth.
Meet James Ty World.
I deliver packages for a living.
I'm a glorified postman.
James is a cycle courier,
one of the riskiest occupations in the world.
There's a fact that there's danger about it,
but that's what draws people to it.
I suppose it's the adrenaline factor.
Research has shown that cycle couriers
are three times more likely to injured
than those in other jobs.
And danger can come from any direction.
People aren't looking for cyclists,
so pedestrians will cross the road.
People that turn left on you.
People that do U turns.
And that's the danger, is knowing that your
not in people's conscience.
You've got to expect things to happen.
Jame's life might be more hazardous than most.
But, the fact is, we all live in a hostile world,
a place full of unexpected threats.
This program will show you just how hard
your body has to work to keep you safe
because as well as protect you
from the more obvious physical dangers,
it must shield you from potentially lethal solar radiation.
It must keep in check the 10 trillion bacteria
that cover your skin.
It must deal ruthlessly with any invaders.
And if things go wrong, immediately heal the damage.
Your body does all of this
without you're having to think about it.
And it works so effectively
that some of us will live for 100 years or perhaps more.
I've got 21 great-grandchildren, now.
I even have one great-great-grandchild.
Esther Tuttle is in her hundredth year,
and she's in great shape.
In the morning when I first get up,
I do my yoga to exercise every muscle in my body
that I can think of.
And then I go up on the roof
where I take a walk for a half an hour without stopping.
So, then I have a glass of orange juice,
oatmeal and black coffee, no sugar, no cream, no toast.
Over the last century,
she's fought countless wars against
largely unseen enemies.
Well, as a child, I had all the usual diseases.
I had tonsillectomy, and measles, and chicken pox.
As I grew older, I had to have a hysterectomy, at one point.
And I had an appendectomy, at another point.
Then, about 15 years ago, I had breast cancer.
I think that's about all of the diseases I've had.
Esther leads a healthy life
and has access to excellent medical care.
But, perhaps the real reason she has lived so long
is because, like you,
she has her own private army.
Working for her around the clock.
Right now, as you watch this program,
your immune system is fighting to keep you safe,
every single breath you take.
This tiny spec of dust is alive.
It's a fungal spore.
The air you breath is filled with them.
Each spore is looking for a warm, moist home,
and it's just found one in your lungs.
Every minute you breath in a couple of spores
just like this one.
Once it reaches a quiet corner of your lungs,
the spore implants and begins to grow.
Left unchecked, it would fill this entire chamber
stopping oxygen passing from the air into your blood.
Within weeks, you'd be dead.
Fortunately, your body's armed and ready.
It unleashes macrophages,
prowling, remorseless, rewarding killers.
They follow a chemical signal given off by the fungus.
The spore is doomed.
Unnoticed and unappreciated
the macrophage saves your life,
and it does this breath after breath
day in and day out.
But your body is not just protecting you
from tiny, invisible things.
It's also designed to help you cope
with more obvious threats,
like a fast moving stick,
a huge hockey player,
or a hard object coming at you at nearly
a hundred miles an hour.
To survive in the fast-moving world of ice hockey,
you have to be able to react in an instant.
Professional goal keeper, Steve Lyle,
can react in less than 1/5th of a second.
That's just the blink of an eye.
So, how does he do it?
Even before his opponent hits the puck,
Steve has already began to work out
where it might go based on his opponent's body position.
Then, he has to work out
how fast the puck is moving and where it's going.
His brain has to produce an action plan
before it actually does anything,
all based on memories of previous occasions
when he saved goals.
Then, finally, his brain tells his body what to do.
Everything up to now has been done
entirely subconsciously.
It's only at this point, that the goalie becomes
consciously aware that the puck has been hit.
What Steve is doing
is something you do, instinctively,
any time you're confronted by unexpected danger.
But reaction times are only part of the story.
You also rely on muscles.
You have 640 muscles that, together,
make up 40% of your body weight.
Cristian Serra relies on his muscles
rather more than most of us do.
He's a champion of a truly terrifying sport.
He jumps over bulls for a living.
Cristian has no illusions about the dangers.
His fragile body regularly goes head to head
with half a ton of charging muscle.
So, everyday on his farm in eastern Spain,
he hones his muscle.
In this form of bull fighting, known as recortes,
it's the men who risk their lives.
The bulls are unharmed,
but no less bad-tempered.
First in the ring, are some of Cristian's competitors.
They're not allowed to use weapons or armor.
Instead, they rely on speed and agility
to dodge a gruesome goring.
It's now Cristian's turn to enter the ring.
As a champion recortadore,
he takes some of the greatest risks.
Risks, that even with all his experience,
he finds scary.
Escaping uninjured will depend
on how his muscles respond in the next few moments.
We all have two different kinds of skeletal muscle fibers.
Just like a chicken, we have dark and white meat.
You use your dark, slow-twitch muscles,
for things like walking.
They work tirelessly, for long periods of time.
So, they need a constant supply of oxygen-rich blood.
But, you also have white fast-twitch muscles,
which allow you to react quickly.
And these are the muscles Cristian's about to use
to try and leap over the bull.
(cheering
When you're dodging a bull,
you don't have time to burn oxygen for power.
So, these fast-twitch muscles do something ingenious.
They rely on a rapid chemical reaction
that allows them to constrict four times faster
than slow-twitch muscles,
which gives Cristian just enough time to escape.
In some sports, muscles and reaction times
aren't enough to keep you out of danger.
Being hit with the force of up to 1/3 of a ton
means that getting damaged is an occupational hazard
for a boxer.
Fortunately, your body is incredibly good
at healing injuries.
And that's something that boxer, Johnny Greaves, relies on,
because he gets hit, a lot.
Tonight, Johnny is fighting a man whose three inches taller
and five years younger.
I'm a professional pounder.
I fight week in, week out.
I get all the tough jobs against all the up and coming boys,
the good ticket sellers.
I basically get paid to fight.
I do a good job.
For Johnny, boxing isn't just a sport.
It's his lively-hood.
I'm here primarily to pay my bills
and to keep my kids okay.
So, obviously, that's the first thought in my mind,
is bringing home the bacon.
Johnny has fought in 53 professional fights.
He's only won two of them.
He knows that tonight he's likely to get hurt.
Johnny works hard to avoid serious injury.
He ducks and dives, dodging punches.
He works at a frantic rate
to keep himself a moving target.
But as Johnny tires, his defenses begin to fail.
Then, he gets injured.
The delicate blood vessels that wind through the fat cells
under his eye, are destroyed by a punch.
As the vessels burst, blood cells rush out.
On the outside, the full extent of Johnny's injury
is not yet obvious.
But, a black eye is about to form.
What his body does next is normal
and, yet, also utterly remarkable.
It begins to heal.
A repair crew is already on the way.
Traveling in the blood,
are some very special cell fragments.
Called platelets, they are there to stop the bleeding.
They extend arms that stick to each other
and form a net to catch the leaking blood cells.
This clot plugs the hole, and the bleeding stops.
But, this is just the start.
Soon after the fight, Johnny's eye turns red
and begins to swell.
It's caused by fluid seeping into the tissue around his eye.
The fluid is coming from tiny pores in the blood vessel.
This is not a sign of damage.
It's actually a rather clever form of defense.
The force of the flow would stop any infection
in the wound from traveling into the bloodstream,
trapping it in the tissue instead.
Johnny's eye isn't just puffed up.
His bruise has now turned a lurid shade of purple.
The color is the result of decaying blood cells,
trapped outside the circulatory system.
Here, they can't survive.
Now, Johnny's body starts to clear up the mess.
Scavenging macrophages sweep through the tissue
and gobble up the dying cells.
Inside the macrophages, the chemical that give bloodcells
their red color, hemoglobin, begins to break down.
It's this that gives the bruise it's
familiar cocktail of colors.
As the hemoglobin breaks apart,
it transforms into different colored chemicals.
Over time, the color shifts from green to yellow
and finally to brown.
As the microphages leave,
they draw the colored chemicals away from the skin.
Healing is now complete.
Two weeks later and Johnny is fighting fit once again.
So, he can step back into the ring to earn his living.
Your body is brilliant at dealing with damage.
But prevention is always better than cure.
And when it comes to prevention,
the most impressive defense you have
comes from the largest organ in your body,
your skin.
Each centimeter of your skin
is built from 10 million individual cells
and bristles with over a hundred hairs.
It acts as a formidable barrier against the threat
of the outside world.
That's something that Jamie Donaldson is counting on.
She's a math teacher, but she leads a double life.
Jamie is about to run equivalent of five marathons
in the hottest and driest place in North America,
Death Valley.
It's neat to see what the body
is really capable of doing and to prove that
you can do a lot more than you think you can.
Here, temperatures can reach 56 degrees Celsius.
Water evaporates faster than almost anywhere else on Earth.
Three, two, one, zero.
Jamie has entered the Badwater Ultramarathon.
She'll be running across this inhospitable environment
for over 24 hours nonstop.
And Jamie will be relying on her skin
to protect her from the brutal heat.
In the desert, you never really do know
what's going to happen to your body.
It's extremely hot.
Jamie's greatest threat is dehydration.
Every step, the parched air,
is trying to suck the moisture out of her body.
What stops her shriveling up like a prune
is a substance made by the skin,
that most of us casually wash away every morning.
At the base of every hair on your body
is a tiny sebaceous gland.
It squeezes an oily substance, called sebum,
onto the surface of your skin.
It makes your hair greasy,
and gives you spots.
But this oil also makes your skin waterproof.
Waterproofing is essential in hot, dry climates.
Because sebum doesn't just keep water out
it also stops bodily fluids from evaporating
into the desert air.
As well as the heat, Jamie also has to contend
with the glare of the sun.
Getting sunburnt would seriously affect her chances
of finishing the race.
So, her dedicated support crew makes sure
she's constantly covered and protected.
Ultraviolet radiation in the sun's rays
breaks down the DNA in skin cells.
Your skin responds by flooding the area with blood
to repair the damage.
This heats up the skin and produces
the familiar redness of sunburn.
But there can also be long-term damage.
By next morning, Jamie is still running.
She has covered 135 miles in record time.
Twenty-six hours, 16 minutes, a new women's record.
Jamie Donaldson, here's your medal.
Most of us have some control over
how much we expose ourselves to the sun's rays.
But, there's another threat that we can never get away from.
Each square centimeter of skin has 10 million bacteria
camped out on it.
The tissues inside your body would provide
a nice, juicy environment, if only they could get in.
What keeps them at bay is the way
your skin cells lock together, just like armor plating.
But, your skin is also pushing outwards.
As new layers grow, the old surface layers peel away,
carrying a cargo of microbes with them.
But this also means you lose 30,000
skin cells every minute.
By this time next month, you'll have replaced
all the skin on your body.
Your skin is an absolutely fabulous barrier.
But, unfortunately, it does have holes in it,
like your eyes, and your nose.
These are very vulnerable to infection.
In particular, when viruses use our own
defense mechanism, sneezing, against us.
A sneeze is all it takes for microbes to jump
from one person to another.
The main reason you sneeze is to clear your nose
of dust and other fine particles.
But as you blast out air, at up to 100 miles per hour,
you also spray a fine mist of droplets
containing millions of microbes,
anything up to 12 feet away.
Giving the microbes the perfect opportunity
to find a new host.
If they do get inside you,
the body quickly responds by mobilizing an army
of white blood cells.
These are called phagocytes.
They eat things.
In this case, they're attacking little, green blobs
which are fake bacteria.
In just one tiny drop of blood
there are around 400 thousand of these white cells.
This is just a tiny fraction of the forces
your body can call on to fight infection.
Do you know that letter?
Yeah.
Rowan O'Brian is three years old.
He should be at school, but he's feeling unwell.
What letter is that one?
M.
That's it. That's it.
He's got the flu.
One, two, three, four, five.
Inside him, his body is about to engage
in all out war with one of the most
infectious viruses on the planet.
Flu viruses start by attacking the tissue
at the back of your throat.
But, strangely enough, it's not only the virus
that will make you feel ill.
It's also your own immune system.
Your body's first response to infection is fever.
The flu virus thrives at your normal body temperature
of 37 degrees Celsius.
So, you raise your temperature by a few degrees.
It's just enough to slow the infection down.
Meanwhile, an army of phagocytes flood the infection site.
They have come to feast on their enemies.
But, instead of destroying the viruses,
the fighters are, themselves, infected
and are forced to self-destruct.
As their bodies pile up,
they form the basis of your snot.
Rowan's symptoms are getting worse.
It's a sign the battle inside him is hotting up.
His body has launched a second wave of attack.
The killer Ts.
They hone in on the throat cells
that have been infected by the virus.
They administer the kiss of death
destroying the viruses inside.
But this approach has it's cost.
The killer Ts are causing heavy collateral damage.
Rowan is feeling the effects.
He's got a really sore throat.
Despite everything, the virus remains undefeated.
Now, your immune system tries
a completely different approach.
Instead of trying to destroy the virus head-on,
it releases a cloud of Y-shaped antibodies.
These are specifically produced to destroy
this strain of virus.
They coat the viruses, making them stick together.
Now, they are easily swept up.
Rowan finally starts to feel better.
And with his energy restored, he can go back to doing
what three-year-old boys do best.
As well as working hard to protect you from infection,
the human body is very versatile
when it comes to dealing with other medical emergencies.
It can mend damaged nerves,
plug leaking blood vessels,
regenerate broken bones,
heal your skin,
and repair ripped muscles.
Your body is so adaptful, it can even be encouraged
to accept and repair part of someone else's body.
Buns, let's see.
Put the buns right here.
Richard Edwards is a chiropractor.
He has a loving wife and family,
and considers himself a lucky man.
But, five years ago Richard was caught in a freak accident.
The gril is hot guys.
He found himself trapped in a burning vehicle.
Everything was on fire behind me,
and my electrical system had burned up,
and I couldn't unlock me door.
I couldn't even manually life up the lock.
I was having trouble breathing, and I quickly looked
over the passenger side to see if it was unlocked,
so maybe I could get out that way.
As soon as I looked over the passenger door,
I remember seeing the window on the passenger side
just explode into several thousands
of pieces of glass.
I'd already started burning alive.
Every time I open one of these things, hon,
that blast from the heat is a memory of
one of those moments in the truck.
The heat from the fire
left 30% of his body severely burt.
With medical help, most of his injuries have now healed.
But his hands were too badly damaged.
He can't button buttons.
He can't do a zipper very easily.
I have to look around a restroom and find a guy
that I think is maybe the least masculine,
and ask,
"Would you mind unzipping my pants for me?"
But this fire has really put a stop to my life.
I want to be able to go back to work and grab an x-ray,
and separate one sheet of x-ray from another,
and talk to patients about how I can help them again,
instead of checking out of life,
like I have done for the last couple of years.
Richard has decided to undergo a radical operation.
It will push his body's ability to heal
to the absolute limit.
A very unusual package is being delivered
to a hospital in Louisville, Kentucky.
With just a few hours notice,
Richard is rushed to the hospital.
He's about to have a double hand transplant.
His hands will be cut off and replaced with someone else's.
97 over 54 is his blood-pressure.
It's the first time
something as radical as this has ever been attempted.
Okay, have you guys decided
who's going on what team to start?
The operation will be masterminded
by Dr. Warren Breidenbach.
They'll be four teams
working simultaneously at one point.
They'll be two teams on each of the arms
that we're preparing, that is the patient himself.
They'll be two teams working on the arms
that came from the donor.
The new hands have come
from someone who died in the last 15 hours.
It's a race against time to connect them
to Richard's blood supply before they begin to deteriorate.
Okie-dokie. That arm is ready
to shake, rattle, and roll.
Do give Richard's body the best chance
of accepting the new hands, both the donor's blood type
and bone structure, were matched to his.
Can we Twitter that the surgery is started?
It's going to be a long night everybody.
The first thing they do,
is prepare Richard's damaged hands for amputation.
His nerves and blood vessels need to be carefully preserved.
Let me have the knife.
The same is done to the vessels in the donor arm.
Don't through any of those veins away.
Save the veins as though they're going to work.
Once his hands are off, there's no going back.
The donor arm came off at 5:30.
So, we're 5 1/2 hours now.
So, we want to get some blood into it.
Very carefully, the new hands are attached,
vessel by vessel, nerve by nerve.
Next, 54 bones and 56 muscles have to be connected,
so that Richard will be able to control his new limbs.
Find the motor branch, yes.
Dissect it back in here, and connect it to that.
After 18 hours of painstaking surgery,
the new hands are attached.
The hand looks pretty pink.
Everything looks good.
Pretty cool, huh?
Just 10 hours after surgery,
Richard sees his new hands for the first time.
It will take months for his body
to complete this remarkable repair job.
Thanks, doctor.
You're welcome.
You can go ahead and let this go down.
But astonishingly, Richard is already able
to take control of someone else's hands.
Let's go ahead and get them moving.
Pull that down.
That's good and strong.
Pull that down.
That's pretty strong.
Remember the one we tightened up?
It's good and strong.
Pull it down, the little finger.
That's strong.
Very thankful to have a new pair of hands.
I've waited a long time for this.
Now, and for the rest of his life,
Richard will have to take drugs,
to suppress his immune system
and prevent his body rejecting the new alien hands.
But if the drugs work,
his bones will fuse together
with the bones of the new hands.
They will join as one.
Blood will flow from his body into the donor tissue.
And the nerves of his body,
will grow, connect, and control what were once,
a stranger's hands.
Three months later,
Richard is trying out his new accessories.
Back to the tough stuff.
He's gained some sensation in his new fingers.
And these hands are already changing his life.
It hits us, I think, every single day,
about how amazing, how miraculous, it is
to have a brand new set of hands on me,
when we thought I was never going to be able to
have another set of hands.
I had to live with what I had.
His body is beginning to take full control of them.
They really look like they belong and fit, fit him.
Oh yeah, they feel like my hands,
in every way.
She loves them.
These are his hands to me, and...
At least I can see that in her eyes.
Richard's recovery is impressive.
Nice catch.
Did y'all get that?
A real tribute to his on resilience
and to the skill of his medical and surgical team.
I can hold her hand again.
Now I can do it.
We are, each and every one of us,
biological marvels,
able to adapt to a challenging world.
Although we have our differences,
we are fundamentally all the same.
We smile using the same muscles.
We see the world with the same eyes.
We have the same hearts,
which work around the clock to keep us alive,
tirelessly pumping blood,
picking up oxygen from our lungs,
and transporting it to every cell in our body.
We have such remarkably efficient life support systems
that we can survive on water
and just a small amount of food,
and that nourishment feeds the most complex brains
that have ever existed.
Each of our brains has 100 billion cells
that are constantly processing a mass of information
rushing in through our senses.
We all began the same way,
when a precious egg and a single sperm
came together, creating a new individual, you.
As our hearts began to beat,
we grew from a tiny embryo
into the 100 trillion cells that make up every one of us.
And your body is so well put together
that with a little careful mantainence
it can last a hundred years or more,
just like Esther Tuttle.