We’ve talked about what happens when you die,
It shows that proved to be very popular.
We think it’s only right we now talk about
how you came into this world.
We don’t know exactly how they came up with this number,
but some scientists say that
the odds of you being born were one in four hundred quadrillion.
Yep, you are special, and don’t ever forget that.
没错 你很特别 永远记住这一点
First there were the odds of your father hooking-up with your mother,
and one scientist told Business Insider that those odds were one in twenty thousand.
Then you have the odds of them staying together,
getting past the first date, then the second,
and staying with each other until they decided to have you.
We are told to get to this point the odds are around one in forty million.
Now come the big odds,
because your mum will be born with one to two million eggs
( 500 of which will be ovulated )
and your dad will make around 500 billion sperm.
Basically, the fact that one sperm met one egg and made you is pretty amazing.
从根本上来说 一个精子和一个卵子相遇并造就出了你 这真的好神奇
we also have to remember that for your parents to exist their ancestors had two to
going back to the beginning of the human race.
You being born was nothing short of a miracle.
So, we know that for you to exist many things had to happen.
But let’s just talk about the day or night that started you off.
We are sure you have had enough education to know that
for you to exist your mother and father had to make love.
Not many people like thinking about this,
but that’s just what happened.
You probably also know that each time people make love
without any kind of contraception,
it doesn’t mean guaranteed pregnancy.
There are many factors,
including the age of the people as well as when they made love
and the people’s reproductive systems.
Some people have to try very hard to make a kid,
while other couples can’t seem to miss.
One doctor from the Women’s College Hospital and St. Joseph’s Health Centre in Toronto said that
if the woman is under 35 she has an 85 percent chance of conceiving in one
year when making love in each menstrual cycle.
The average cycle lasts 28 days.
The woman will ovulate after her period.
The ovulation part starts about 14 days on average
after the first day of her last period.
In many cases this part will happen about two weeks
before the woman has her next period.
The woman will make an egg which is released by the ovaries
and it is passed down the fallopian tubes where it can meet a sperm.
This lucky sperm can then fertilize the egg.
And voila, the process of making a baby is on the way.
To make a baby you don’t need to wait for the ovulation period,
and you might not know
that a man’s sperm can wait inside a woman for this egg to be made.
It’s said sperm can live in a woman about 5 days,
although most don’t survive that long.
OK, so we know that a woman needs to produce an egg
就是这样 所以女性需要排卵 而且
and a sperm has to reach that egg and fertilize it.
But did you know that
a man will create around 525 billion sperm cells in a lifetime,
something which led the now deceased comedian Bill Hicks to say
he has wasted entire civilizations from releasing sperm when not making love.
Live Science tells us that just one single shot
can carry up to 40 million to 1.2 billion sperm cells.
Hmm, why on earth do we need so many of these things?
Scientists tell us the reason is basically because of competition.
The more sperm, the better chance one will get to the egg.
The highest sperm producers have the better chance of passing on their genes.
The distance the sperm has to travel to meet the magic egg is only 15 centimeter,
but this is no easy swim.
Some of them just flow back after take-off,
while others are killed by acidic fluids inside the woman.
These are basically non-starters.
But of the many millions that are launched,
about two million make it to base one: the cervix.
Here some just run into walls and die,
while others get trapped in mucus.
It’s quite the race for those sperm and always fraught with danger.
However, about one million will make it to base two: the uterus.
Unfortunately, many come un down here and get taken out by white blood cells.
About 10,000 are now left and have made
it all the way to the top of the uterus.
They then head to the oviduct,
and women have two of those but rarely make eggs in each.
That means about half of those dear sperm choose the wrong door and there’s nothing behind it.
The ones that went the right way will have to face the uterotubal junction,
a place where the oviduct and uterus is connected.
This busy junction is tricky for the sperm to get through,
and many get stuck in mucus.
From millions we now have about 1,000 survivors heading to
where the star prize is kept down the fallopian tubes.
Many don’t make it all the way to the egg and just die,
a sad thing when you think how far they made it.
But it gets worse, because there can be only one,
in the words of the Highlander.
Something happens called a Cortical reaction,
which is basically the woman’s egg blocking out multiple sperms.
Sometimes there is a winner,
and that tough sperm that won one of the hardest races in
the world is a part of you.
It’s by no means a done deal, though,
as there is a chance of miscarriage.
This often happens early,
and if a woman gets past the 14-week mark,
she only has one percent chance of losing the baby.
So now we are in business,
you are on your way to being born.
There are stages of pregnancy and we call these stages trimesters.
The entire pregnancy should last on average about 40 weeks,
but as you know, some babies come out early.
From the 1st week until the 12th week we call the first trimester.
During this time the woman will likely notice a few changes,
such as possibly having mood swings, parts of her feeling swollen, feeling nauseous,
比如可能有情绪波动 部分人会感觉浮肿 恶心
having food cravings, or getting a headache or heartburn.
想吃东西 头痛 或者胃灼热
But what is happening inside?
For the first couple of weeks there isn’t much of a you yet.
About one week after the sperm won that race and met the egg,
the fertilized ovum attaches itself to the uterus lining and now the placenta starts to form.
At about two weeks the embryo looks a bit like a disc on this wall.
But it’s not until about four weeks that this little embryo starts sprouting things.
The hearts starts to form,
and little buds develop where the legs and arms will be.
All this is only about 1/25 of an inch.
The ears, eyes, nose, all start to develop,
耳朵 眼睛 鼻子 都开始发育
as do the spine and the digestive tract.
At about 8 weeks we have something a bit more human-looking,
what we call the fetus.
The heart is now properly functioning and the fetus has all the organs (not fully formed)
that the baby-to-be will have.
Nascent bones are also now starting to form.
At 12 weeks we are starting to see a tiny human,
replete with larger head, genitalia,
tooth buds, and even fingernails and toenails.
The baby can now move around, too,
in what’s called amniotic fluid.
This is the end of the first trimester.
At the beginning of the second trimester the baby will be
about three inches long and weigh around an ounce.
The head will stop growing so fast
and the eyelids will close as the eyes develop.
Nerves and muscles come into action and now this tiny fetus can even make a fist.
As the fetus is now bigger many women now will have a noticeable bump.
They may also feel a bit better and
stop having those awful feelings of nausea.
Saying that, they might also have a lot of new aches and pains.
Under the hood, at 16 weeks the baby’s skeleton keeps developing.
The skin looks white, almost see-through.
The fetus at this point may have a bowel movement,
but it will be something called meconium.
This is a dark green substance that is pretty much poop.
The fetus is now about four or five inches long and weights around three ounces.
At twenty weeks the little bundle of joy to be might get restless,
and that’s when the woman might start feeling the baby kicking.
Many body parts are now fully formed, such as fingernails and toenails.
We are told it can even start scratching itself at this point.
It can also swallow and hear things.
Moving on to week twenty four during the second trimester
the baby makes its own blood cells from bone marrow.
It now has fingerprints.
It can taste things as taste buds form on the tongue
and it will even get a bit of hair.
The lungs are not properly developed yet,
but that process is on the way.
Whether a boy or a girl,
the fetus will now start developing its own reproductive organs.
Another thing that starts now is a normal sleep cycle.
At this point it is about 12 inches long
and might weigh in the region of 1.5 pounds.
Welcome to the third trimester,
the point in time when the woman is carrying around a lot of extra weight.
There will be discomfort at times,
and that’s just the body reacting to having another thing grow inside of it.
At 32 weeks we almost have the finished package.
The baby’s bones are not fully developed,
but they are getting there.
It can now open and close its eyes.
The lungs are still not fully-formed,
but the baby at this point will be practicing breathing.
At this point the baby is also storing
all the natural minerals it needs to be healthy.
Right now it might be as long as 16 inches
and may weigh about 4 pounds or more.
At 36 weeks something called vernix thickens around the baby.
This is a waxy coating that protects the baby.
It’s now storing a fair bit of body fat,
and that means less space to move around.
The woman will feel fewer of those kicks.
We usually have a fetus now
about 18 inches long and weighing around six pounds.
After this point we have the real deal
meaning the fetus has organs that are fully developed for the world outside.
As the time draws nearer to birth,
the baby may switch into a head-first position.
It’s just a matter of time now
until it comes out and takes its first breaths in the world.
When it does it may weigh about 6-9 pounds, but that can change.
Its length might be around 20 inches, but that can change, too.
长度可能在20英寸左右 但同样地 也不一定
Then what happens?
Well, in those first moments after it comes out,
the people around may clean the baby and evaluate its health.
It’s nose and throat will be very gently cleared.
The umbilical cord will be clamped in two places and then it will be cut.
In case you didn’t know,
this cord connects the baby to the women’s womb.
It takes oxygen and nutrients to the baby from the placenta.
Anyway, after it is cut it will leave a stump.
This will turn dry and just drop off.
After around 7 days or more the bellybutton should be fully healed.
约7天之后 也许更久 肚脐就可以完全愈合了
What else happens right after birth?
Well, the baby will likely have antibiotic ointment rubbed
on its eyes to stop infection.
It will also receive an injection of vitamin K to help its blood clot.
As we said, doctors will check if the baby’s health is good,
but another important thing is to make sure its temperature is right.
If all is good, after a few hours it may get a sponge bath.
It will then likely get a little cap to wear to keep its head warm
and in time will get its first taste of mother’s milk.
Baby and mother can usually go home after 24 to 48 hours,
but more tests might need to be done.
You might also have to visit the hospital again
just for a check up after a week or so.
And that’s that,
this is how you were born, or close to it.
We’ve all been there and we are all lucky in some ways to be alive.
我们都经历过 从某些方面来说 能够活着我们都很幸运
An indomitable sperm met with an almighty egg
after your mother and father had performed nature’s life-giving dance
How cool is that.
If you found this video interesting,
I suggest you check out our most popular video, What
Happens When You Die?
Thanks for watching, and as always,
don’t forget to like, share and subscribe.
不要忘记点击点赞 分享 订阅喔
See you next time.
We’ve talked about what happens when you die,