生命不可思议的旅程 The incredible journey of life
从出生，经历婴儿期，童年期，青春期，成年 From birth through infancy, childhood, puberty, adulthood
逐渐成熟直到老年 And the slow maturity to old age
这是我们生命的故事 This is the story of our lives
从独特的视角，从身体内部揭示身体是如何运作 From the unique perspective, deep inside how body is working
这是一个人类个体生命的旅程 This is the journey of a human life
从外，至内 From the outside, in.
胎儿在子宫内发育 A fetus develops in the womb
这个惊人的40周旅程，经历了从一个单细胞到临盆婴儿的全部过程 It's astonishing 40-week journey from a single cell to a baby ready to be born.
它的身体是微观设计的奇迹 Its body is a miracle of microscopic design
微小而完美的器官。每一个都由数十亿完美工作的细胞组成。 Tiny, perfectly formed organs. Each made up of billions of perfectly functioning cells
这些细胞是我们身体的基石 These cells are the building blocks of our bodies.
他们让我们成为人类。一百万亿个细胞都在和谐中工作着。 They make us what we are. A hundred thousand billion cells all working in harmony
在每一个细胞中都有相同而特别的引擎 Inside every cell is the same extraordinary engine.
一台能告诉每个细胞如何生长的机器 The machine that tells each cell how to grow
以及告诉他们应该实现什么样的功能 and what functions to perform.
每个人的DNA都是独一无二的 DNA is unique to every person.
它是化学物质构成的，形成新生命的指令的蓝图 A chemical blueprint of instructions that creates each new life.
这个婴儿已经准备好降临这个世界了 This baby is ready to enter the world.
作为一个人，他即将开始他的旅程 A new born person who's journey is about to begin.
这个旅程即从挑战开始：呼吸，或者死亡 The journey starts with the challenge, breath, or die.
它的肺部还从未呼吸过 These lungs have never breathed before.
肺里还仍然充满了保护肺部长达9个月的羊水 They are still full of amniotic fluid that protected them for 9 long months.
这个新生儿面临“淹死”的威胁 The new-born is endanger of drowning
随即，身体进入了“生存模式” Then, the body kicks into survival mode.
位于肾脏上部的肾上腺释放出肾上腺素，随血液传递至全身 The adrenal glands, right above the kidneys, send adrenalin surging around the body
肾上腺素激活了肺部 It shocks the lungs into live.
呼吸所需的肌肉开始痉挛 Muscles we need to breathe suddenly start to spasm.
于是我们第一次呼吸 And we take our first breath.
这是我们一生中最重要的一次呼吸。七百万次的第一次。 It's the most important breath of our lives - the first of 700 million.
我们活着的每一秒肺部都在抽气 Our lungs will pump air every single second as long as we live
空气冲下呼吸道，经过数千的分支管道 Air rushes down the wind pipe. down thousands of branching tubes.
最终进入将近三千万微小的称之为“肺泡”（Alveoli）的空气袋中 And into nearly 30 million tiny air sacks - alveoli.
这些气袋将氧气推入我们的血液中，并从中抽取二氧化碳随我们呼出 These air sacks pull oxygen into our blood, and pump out the carbon dioxide we exhale with every breath.
80年的生命中从未停止过 and they do it non-stop for 80 years
出生的那一刻开始，万事万物都发生了改变 At the moment of birth, everything changes.
母亲和婴儿之间的物质连接第一次中断了 The physical link between mother and baby is broken for the first time.
出生的第一个小时发生了快速的变化 The first hour brings rapid change.
婴儿身上所有的器官都被迫适应在子宫外存活 All the baby's organs have to adapt to life outside the womb
这是一个富有挑战性并且很危险的时刻 It's a challenging and risky time
在这个年龄，心脏不比核桃大 At this age, the heart is no bigger than a walnut.
心脏已经在子宫中工作了8个月。然而现在，心脏却有可能导致停止的缺陷。 It's been pumping in the womb for 8 months. But now it has flaws that could be fail.
在主动脉和心脏中有两个空洞 Two holes, one in aorta and one in the heart.
在子宫里时，这两个洞让血液能绕开我们还不在工作状态的肺部 In the womb, they diverted blood away from our inactive lungs.
然而现在我们需要肺部，所以这两个洞必须关闭密封 Now that we need the lungs. The holes seal shut.
心脏正常的工作着 The heart is working normally
将血液输送到成百上千 pumping blood through tens of thousands
英里的血管中 of miles of blood vessels
其他系统也在准备中 Other systems are also gearing up.
消化道 The digestive track
已经为第一餐而清空，腾出空间 is ready to clear itself out to make room for its first meal.
肠道充满消化过的羊水和死细胞 The bowel is full of digested amniotic fluid and dead cells
这种粘稠的墨绿色沥青状物质称谓“胎粪”(Meconium) A sticky green black tar like material called Meconium.
胎粪是具有腐蚀性的物质。如果在分娩时不幸落入婴儿肺中 It's corrosive stuff. If it ends up in the babies’ lungs during labor
就会危害到精巧的肺部结构 It can attack the delicate lining
然而在肠道中，胎粪是无害的。 But here in the gut, Meconium is harmless. The digestive track
消化道在几天内就能将其排空。 flushes it out within days.
随着时光的流逝，越来越多更为复杂的系统开始启动 As time passes, more sophisticated systems starts to kick-in.
下一个挑战是寒冷 Our next challenge is the cold.
在子宫内的温度是100华氏度，摄氏37度 然而在家中 It was 100 degrees in the womb here at home,
仅为17摄氏度的气温冲击着身体系统 65 degree room temperature is a shock to the system
控制温度的部分 The area that controls temperature is
位于大脑中较深的区域 deep within the base of our brains.
当一个成人感到太冷 when an adult is too cold
或是太热时，这个区域发出指令到身体，以制造更多或更少的能量 or hot, this area sends out instructions for ourselves to produce more or less energy.
这个区域称为“下丘脑”（Hypothalamus） It's called the Hypothalamus. And like all our
同我们其他所有的器官一样，在这个年龄 other organs at this age
下丘脑仍未发育 It's still immature.
大脑处在压力中。每秒进行一百万亿次计算，仅仅为了让身体工作 The brain is under pressure. Making 100 trillion calculations per second just to keep our bodies functioning.
然而它却还在学习如何做到。所以我们处在“体温过高”（Hyperthemia）的危险中 But it's still learning how. And now we are in danger of Hyperthermia.
红外线摄影机展示了我们的身体在损失宝贵的体热的时候 An inferred camera shows the struggle to keep warm
如何挣扎着保持温暖 黄色区域是我们失去热量最多的地方 as we lose precious body heat. The yellow areas show where we lose the most.
幸好我们准备好了。 在我们的血管和重要器官周围 Luckily we are prepared. A layer of special tissue
环绕着一层很特殊的组织，不停产生热量 around our blood vessels and vital organs actively generates heat.
这就是脂肪 It's fat.
然而这是一种特殊的脂肪 But this is irregular fat.
称为棕色脂肪。通常只在冬眠动物体内存在。 It's brown fat. A specialized type usually found in hibernating animals
脂肪外包裹着特别的产热细胞 It's packed with special heat generating cells.
最终，大部分这种脂肪都会溶解。因为下丘脑逐渐成熟，肝脏和其他器官 Eventually, most of this fat will melt away. As the Hypothalamus matures, and the lever and other organs take on the job
逐渐接管热量的产生 of generating heat
仅仅几个小时大，我们对周围的世界 Just hours old, we know almost
还一无所知 nothing about the world. Everything we
我们所依赖的一切仅仅是直觉 we do relies on instinct
感觉现在还仅仅是反射而已。 正常情况下，我们对呼吸的控制并不多于对吮吸的控制 feeling is a reflex. Normally, we have no more control over sucking than the urge to breath.
这是乳汁第一次经由“食管”（Oesophagus）到达胃中 This is milk on its first journey down via Esophagus to the stomach.
母亲的乳汁比“终极”超级食品更为重要 Mother's milk is much more than the ultimate super-food.
乳汁同样保护我们免受隐藏威胁的危害 It also protects us from hidden danger.
在子宫外，细菌无处不在 Outside the womb, bacteria are everywhere.
无形，并且有致命的可能 Invisible and potentially deadly.
我们仅仅一天大的皮肤不断受到攻击 Our day-old skin is under constant attack.
在我们的体内和体表，存在的细菌比细胞的10倍还多 There are 10 times more bacteria than human cells in and on our bodies
然而我们的免疫系统还未发育成熟。因此，我们自己不能抵抗感染。 Our immune systems aren't developed yet. So we can't fight infections for ourselves.
令人惊讶的是，我们的母亲帮助我们 Amazingly, Our mother
借由母乳消灭他们 fights them for us through her milk.
母亲和婴儿间紧密的联系 The close contact between mother and baby
意味着攻击婴儿的细菌同时也攻击母亲 means she observes the same germs that attacking us
她的免疫系统产生抗体 Her immune system creates antibodies.
接着，借由母乳，她将这些抗体传送给我们 Then she delivers those antibodies back to us, in her milk
直到我们自己的免疫系统发育完成之前 Until our own immune system developed
她会保护我们安全 She will keep us save.
现在是踏入世界的时候了 It's time to take on the world.
从出生到现在已经四周了 It's been 4 weeks since birth.
婴儿已经喝了将近30品脱的牛奶 （14升） The baby has drunk nearly 30 pints of milk.
并且增加了2磅（将近1公斤）的体重 -- 占其体重的四分之一 And it has put on 2 pounds - 1/4 of its body weight
现在是到户外活动的时间了 It's time for its first trip outside.
一个月大 1 Month
哪怕是到附近小商铺，也能让婴儿的感官超载 Even a visit to the grocery store can overload the senses
嘈杂，明亮，而且充满各种气味 It's noisy, bright and smelly
鼻子一直在工作着 The nose is working over time.
在鼻腔内的高处，特化的神经细胞悬挂在气流中 High up inside, specialized nerves dangle in the air stream
他们检测空气里的化学成分 They detect chemicals in the air
随后发送电信号给大脑 And send electrical signal to the brain
由大脑解释成嗅觉 which interprets the signals as smells
这些神经超级敏感 The nerves are super-sensitive.
每一种气味都是新的感觉 Every smell is a new sensation.
同样的事情也发生在听觉上。奇怪的新世界 The same goes for our hearing. Strange new world
奇怪的新声音 Strange new sounds.
声波振动鼓膜 Sound waves vibrate the air drum.
在鼓膜另一侧，这些细小的骨头，“听小骨”（Ossicles） On the other side of the air drum, these tiny bones, the Ossicles,
随之振动 vibrate in response.
这些骨头是体内最小的骨头 They are the smallest bones in the body.
然而没有他们 我们什么也听不见 but without them, we will never hear a thing.
听小骨利用杠杆原理放大震动 They use leverage to amplify the vibrations.
击打鼓膜22次 Hitting the air drum 22 times
已扩大的震动现在进入内耳，或者“耳蜗”（Cochlea） The amplified vibrations now enter the inner ear, or Cochlea.
这里排列着精巧的纤毛 It's lined with delicate hairs.
当震动经过时，纤毛跟着震动 When vibrations pass through, the hairs vibrate.
在基部，有无数脆弱的纤毛，负责高频率的声音 At the base are the fragile hairs for high frequency sounds.
而在顶部，则是负责低频声音的纤毛 At the top, low frequency hairs.
每一个都比头发细200倍 Each one, 200 times thinner than our hair on our head.
然而，随着时间的推移，大音量的声音会损坏这些纤毛 Over time, loud noises will damage these hairs.
但在当前这个年龄，纤毛是完美的 But at this age, they are perfect.
而我们的听力也永远不会再像现在这么好 Our hearing will never be this good, again.
视力却有所不同 The story is different for eye sight.
我们出生时，视力尚未发育 We are born with very underdeveloped vision.
哪怕一个月大时，世界对我们来说仍然模糊不清 Even at one month, the world is blurred.
并且大部分是黑白的 And mostly black and white.
我们视力的每一个方面都是初级的 Every aspect of our vision is rudimentary.
眼内的肌肉还未成熟。我们还不能朝着想要的方向看。 The eye muscles are immature. Keeping us from pointing your eyes where we want to.
在眼内，调节“镜头”的肌肉也无法运动，眼睛无法对焦 Inside the eye, the lens muscles still can't focus.
“镜头”颠倒传递过来的图像 And the lens flips the image it receives.
我们一生中所看到的世界，都是上下颠倒的 All through life, we see the world upside down.
图像在我们脑中得到调整 The picture only gets reoriented in our brains.
现在，图像在视网膜（Retina）上 Right now, the picture is on the Retina.
视网膜在眼球后部 The screen at the back of the eye.
视网膜上有两种细胞 The Retina has two types of cells.
视杆（Rods）细胞和视锥（Cones）细胞 Rods and Cones
他们将撞在他们身上的光转化为电信号 Which transform the light that hits them into electric signals
视锥检测颜色信息 The Cones detect color information.
然而此时视锥还未发育 But because they are not developed yet.
出生的头一个月，我们只能看见黑色和白色 We see mostly in black and white during our first month.
视觉信号沿着两根较粗神经，从视网膜出发到达大脑下方 From the Retina, the signals travel along 2 thick nerves under the brain.
神经的尽头是我们处理视觉信息的区域 At the back is where we process visual information.
当图像到达时，真正的挑战开始了 When the image arrives, the real challenge begins.
我们不成熟的大脑还未学会如何解释数据 Our immature brains haven't learned to interpret the data yet.
然而我们学习飞速 That's changing fast.
两个月大时我们已经可以分辨颜色和形状 At 2 months we can distinguish colors and shapes.
四个月时，我们能识别出母亲的脸 At 4 months, we can identify our mother's face.
八个月大时，我们已经有了20/20（近似于5.0）的视力 注：20/20的视力表示在20英尺的距离能看清正常的物体 By 8 months, we have 20/20 vision. (If you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at that distance.)
随着视力日趋完美，我们也急速成长 Along with our perfect eye sight, comes a grow spirt
我们开始增肥 We start packing on pounds.
每个月我们都增加占身体1/4的体重 We add 1/4 to our body weight every month.
三个月大时，生长变缓慢了 After 3 month, it slows down.
幸运的是，如果我们持续那么快的生长下去 Lucky for us. If we kept growing that fast,
四岁时我们能达到150吨重 we weight 150 tons by age 4
与一头蓝鲸相当 the same as a blue whale.
八个月 8 Month
八个月时，我们所有感官都正常工作了 At 8 month, all our senses work.
我们开始探索这个世界。而我们最常用的感官是 We are beginning to explore the world. And the sense we use most
触觉 is touch
摸到太烫的东西 Touch something too hot
皮肤里的温度感受器就给手臂发送神经信号沿着手臂向上 And temperature sensors in the skin send nerve signals raising up the arm
信号传导到脊髓中枢神经 Up to spinal core
直到大脑中 and into the brain
信号能达到200迈/小时 （300公里/小时） All at 200 miles per hour
大脑检测到信号 The brain detects the signal
并处理为疼痛 interprets it as pain
然后，向肌肉发送信号 and fires another signal back to the muscles
让我们把手拿开 we move the hand away
传感神经受体遍布我们全身 We have sensoring nerve receptors all over our skin
但是身体的某些区域比其他区域更为敏感 But some areas are more sensitive than others
手部，脸部和嘴 The hands, face and mouth.
舌头上，有9000个受体 There are 9000 sensory receptors on the tongue along.
这也是为什么婴儿总喜欢用嘴试探周围的世界 Which is why babies use their mouth to explore
但是还有另一个原因导致婴儿的不安 But there is another reason for all the annoying.
在他们的嘴里现在有一种疼痛 Something painful is happening inside the baby's mouth.
她的第一批牙正在生长出来 Her first teeth are coming through
我们仍在子宫里的时候，乳牙（Milk teeth）就已经深藏在牙龈（Gum）中 Milk teeth form deep in our gums while we were still in the womb
现在他们一个接一个破茧而出 Now, one by one, they burst through
这很疼，但是却有进展 It's painful, but it's progress.
从八个月，到80岁的旅程里 At 8 months into life's 80-year journey
身上的“传感器”都在满负荷运作 The sensors are operating at full capacity
每一种感觉都是一个新的惊喜 Every sensation is a new surprise.
有了新的牙齿，她可以吃更多种固体食物了 And with her new teeth, she can take on more solid foods.
消化始于口中 Digestion starts in the mouth
牙齿研磨食物 Teeth grind up the food
舌头下的特殊腺体分泌唾液 Then special glands under the tongue pump out saliva
唾液帮助瓦解和润滑食物。食物经过12个小时才能穿过13英尺（4米）的肠道 To help break down and lubricate the food on its 12 hour 13 foot journey through the gut
食物要经过胃，到达盘旋的小肠 It'll pass from the stomach into the coils of the small intestine
在最终到达大肠前 before finally passing into the large intestine
肌肉一波又一波的不停收缩，保持食物移动 Waves of contracting muscle keep the food moving
这个过程称之为“肠蠕动”（Peristalsis） A process called Peristalsis
这种收缩运动是如此强大 This contractions are so powerful
以至于我们甚至可以倒立着吃东西 we can even eat up side down
有史以来这是第一次，我们借由一种新的高分辨率摄像机 For the first time, a new camera shows a high definition view
窥视食物是如何进入我们的体内，到达胃中 of how food travels through our bodies and into our stomachs.
食物要进入胃中，必须先经过胃顶部的一个洞口 Food enters the stomach through a hole at the top
我们的胃就是一个肌肉袋子 The stomach is a bag of muscle that churns
将食物搅拌，压扁，挤烂，成为液体 squashes and squeezes food into liquid
同时，胃酸将食物分解 At the same time, acids brake the food down
胃壁受到内层粘膜的保护 The stomach walls protect themselves with the lining of mucous
没有内层粘膜的话，胃酸甚至可以消化胃本身 Without it, the acids could digest parts of stomach itself
导致胃溃疡（Stomach Ulcers） causing Stomach Ulcers
大约一小时后，胃将已经分解的食物经由一个微小的洞挤出 About an hour later, the stomach squeezes the broken down food out through a tiny hole
这个洞成为“幽门括约肌”（Pyloric Sphincter） called the Pyloric Sphincter
食物进入小肠（small intestine） The food enters the small intestine.
我们在这11英尺（约3.5米）缠绕的管道中吸收绝大部分的营养 An 11 foot coil of tube where we absorb most of the nutrients.
小肠的内壁上 The interior wall of small intestine
有着数以百万的微观结构 is lined with millions of microscopic projections
成为“小肠绒毛”（Villi） called Villi
这些绒毛增加了肠道的面积 These increase the surface area of the gut
使我们更容易的吸收营养 making it easier to absorb nutrients
首先，胰腺（Pancreas）分泌出汁液中和胃酸 First the Pancreas pumps out a juice that neutralizes stomach acid
接着，肝脏分泌出胆汁（bile）分解脂肪为微小液滴 Then bile from the lever brakes down the fat into tiny droplets
这些小液滴更容易被小肠吸收 Smaller droplets are easier for the intestine to absorb.
大约一个半小时后 After 1 hour and half
小肠从食物中吸收了大部分的营养 The small intestine has absorbed most of the nutrients from the food
现在到了让残余物质继续往前的时候了 It's time for what remains to move on.
这些剩余物质通过这里进入大肠 It enters the large intestine through this
这是“回盲肠括约肌”（Ileocecal Sphincter） the Ileocecal Sphincter
它是帮我们阻止食物倒流的阀门 a valve that keeps our food from going back where it came from
现在的残余物是无用的食物以及小肠壁上死亡的细胞的混合 What's left is a mix of waste food and dead cells from the walls of the gut
而大肠的主要工作是从残余物内提取水分 The large intestine's main job is to extract water from it
大量的细菌也生活在大肠里 lots of bacteria live here too
但这并不是因为受到感染 but it isn't because of an infection
我们实际上需要这些细菌 we actually need them
他们产生酶来帮助分解食物中复杂的碳水化合物 They produce enzymes that brake down complex carbohydrates in our food
而我们自身无法分解碳水化合物 carbohydrates we couldn't otherwise digest
最终，大约12个小时后 Finally, after about 12 hours
我们排出第一餐的剩余物 we expel what's left of our first meal
12个月 12 Months
一岁大的我们 One year old
我们可以移动了。我们已经将爬行练习至完美 We are mobile. We've perfected the art of crawling
我们的骨头也更加强壮 Our bones are stronger.
他们也需要变得更强壮，因为我们正在变得很重 They need to be. We are getting pretty heavy.
出生时，我们的骨骼主要是“软骨”（Cartilage） At birth, the skeleton is mostly Cartilage.
同形成耳朵的物质一样 The same material as our ears
软骨是很灵活的 Cartilage is flexible.
因为是软骨 我们才能从产道中挤出来 It's what allows us to squeeze through the birth canal
但是出生后，我们柔软的骨骼是一个问题 but after birth, our soft skeletons are a problem
他们需要硬化来支撑生长中的身体 they need to be rigid to support our growing bodies
并且保护我们的重要器官 and protect our vital organs
所以，从一出生起，软骨就开始硬化 So right from birth, the Cartilage starts to harden
有一种特殊的细胞称为“成骨细胞”（Osteoblasts） special cells called Osteoblasts
将矿物质放在软骨上，使之成为硬骨 lay down minerals that turn soft cartilage into hard bone
一些骨头甚至会融合 some bones even fuse together
出生时，我们的头骨版之间有一个空洞 At birth, we have gaps between the plates of the skull
这使颅骨在出生的时候可以变形 which allow the skull to deform during birth
在我们出生后的一年里，这些空隙逐渐愈合 through our first year, these gaps gradually close
直到颅骨完全成型 until the skull is finally complete
骨架发育完成后，我们就有了到处行走的欲望 as our skeletons develop, so does our desire to get around
我们即将到达生命的一个重要里程碑 we are about to hit one of the major milestones in life
双脚站立 standing on two feet
站立的关键并不是强壮，而是平衡 the key isn't strength, it's balance
而站立的秘密深藏在耳中 and the secret to standing is hidden deep in our ears
在负责听觉的听小骨后方 beyond the ossicles - the bones we use for hearing
内耳由三个环形结构构成 the inner ear is made up of three looping structures
每个环都跟10美分一样大 （直径1.8厘米） each loop is the size of a dime
他们能涵盖所有的三个平面 and they are oriented to cover all three plains
这些“半规管”是我们耳朵的一部分，但却不是用在听觉上的 these semicircular canals are part of our ears but they have nothing to do with hearing
充满液体，告诉我们什么是上 they are filled with liquid. and they tell us what's up
什么是下 what's down
和什么是水平 and what's on the level
半规管里的液体冲刷着管壁上的感觉绒毛 the liquid inside slashes against sensor hairs lining the tubes
绒毛向大脑发送数据，告诉我们目前的朝向是什么 the hair send data to the brain about how we are oriented
以及我们的运动方向 and our direction of movement
他们是负责平衡的器官 these are our organs of balance
一旦掌握了平衡，我们又离行走近了一步 once we've mastered balance, we are one step closer to walking
现在再也没有东西限制我们的行动和学习了 now there's no limit to where we can go and what we can learn
从婴儿到幼儿 from a baby to a toddler
我们装载着差不多成形的耳朵 we are embarking on our most formative ears
到了我们该把生长中的大脑 a time when we will put our growing brains
和发育中的免疫系统 and developing immune systems
投入测试的时候了 to the test
两岁 age 2
我们在婴儿期幸存了下来，并且已经能够双足站立 we've survived infancy and can stand on our own two feet
接下来迎接我们的将是人类独有的挑战 next stop is a uniquely human challenge
学会说话 learning to talk
[嘻嘻] 超可爱啊 [xixi]
两岁 2 Years
说话，需要大量的大脑活动 talking takes a lot of brain power
一个两岁小孩一天能记住10个新单词 a 2-year-old learns 10 new words a day
[小女孩:醒过来！] [girl:wake up]
这是“布罗卡氏区”（Broca's area） this is Broca's area
该区位于大脑的一侧，负责产生语言 the region at the side of the brain used for speech production
以及理解 and comprehension
语言区别了我们和其他动物 （不是劳动，使用工具 - -！） language is what separates us from other animals
我们能相互交换复杂的想法和意见 we exchange complex thoughts and ideas
并教导我们的孩子---不光是展示 and teach our children not just by showing
而是“告诉” but by telling
随着我们大脑的发展，我们得到了其他人类特有的能力 as our brains develop, we gain other uniquely human qualities
我们知道我们自己是谁 we are aware our own identities
以及形成了个性 and individuality
我们开始为自己着想 we gain the ability to think for ourselves
五岁 5 Years
我们也开始形成记忆 and we're forming memories
记忆能持续一生 that will last a life time
比如我们上学的第一天 like our first day at school
我们也许能记住我们身边发生的事情 we may remember what was going on around us
但是真正的行动却发生在身体内部 but the real action is happening inside
大脑是由1000亿神经细胞组成物质团 the brain is a mass of 100 billion nerve cells
在神经之间产生的电力 between them, they generate enough electricity
足以保持一个灯泡电量一天 to keep a light bulb burning for a day
细胞使用电脉冲通信 the cells communicate using electric impulses
每一个脉冲都是思想和记忆的微小片段 each impulse is a tiny fragment of thought or memory
当我们听到一个新词 when we hear a new word
[背景:我爷爷的。。。] [background: my grandpa's ...]
我们的耳朵将声音转化成电脉冲送到大脑 our ears convert the sound into electrical impulses in our brains
大脑之所以能学习，是因为脑细胞之间的连结 the brain can learn because the connections between brain cells
并不是永久性的 aren't permanent
大脑能够重新连结 the brain rewire itself
神经细胞长出如同藤蔓的须，称为“轴突”（Axons） nerve cells send out tendrils called Axons
持续不断的形成新的连接 constantly forming new connections
细胞之间连接的地方有一个微小的缝隙 the cells meet at a tiny gap
称为“突触”（Synapse） called a Synapse
化学物质在缝隙中充当桥梁，让脉冲能够继续传送 Chemicals bridge the gap to allow the impulse to continue the chain
新的连结形成一种模式 the new connections form a pattern
最终形成新的记忆 a new memory
我们通过在脑细胞间建立新的连接来学习 we learn by making new connections between brain cells
通过重复加强这种连结 and then reinforcing them through repetition
加强越强 the stronger the reinforcement
记忆越有可能保存下来 the more likely the memory will stay
9岁 9 Years
[老师: “电池”这个词是什么意思?] [teacher: what is the word "battery" mean?]
当有人要我们唤醒记忆 when someone asks us to recall that memory
同样的轴突模式启动，记忆被取出 the same pattern of Axons fires, and the memory comes alive
大脑负责发送信息给驱动手臂肌肉的神经 our brains respond by sending messages to the nerves that drive the muscles in our arms
举手 we raise our hands
[女孩:我会，老师!] [girl: Me Miss!]
在童年期我们大脑的主要任务是学习 in childhood our brains are primed to learn
并且迅速生长 and they are growing fast
快速的生长使我们的大脑很容易形成新的连结 the rapid growth allows our brains to easily form new connections
这种能力随着年龄增长而减退 and the ability that will fade with age
当我们的大脑在不断学习的同时 and while our brains keep learning
我们的身体也在做同样的事情 our bodies do the same
免疫系统的任务是学习识别感染 it's the immune system's job to learn to recognize infections
每一种进入身体的细菌 every germ that enters the body
都带着产生疾病的潜在威胁 carries the potential thread of disease
但首先，细菌必须要能够进去 but first, the germ has to get there
免疫行为并不是从我们身体里面开始的 immunity doesn't begin inside our bodies
我们从细菌接触我们的那一刹那开始，就已经开始与其斗争 we start fighting germs the moment they touch us
我们有一整个“军火库”来抵抗感染 we have an arsenal of defenses against infection
我们的眉毛和睫毛 our eye brows and eyelashes
耳毛 ear hairs
和鼻毛 and nasal hairs
能够捕捉到通过空气传播的细菌 catch airborne bacteria
汗液，泪液和黏液将他们冲走 sweat, tears and mucous wash them off
我们的皮肤不断地脱落表层细胞 our skin constantly sheds its top layer of cells
这些细胞沾染着细菌 taking bacteria with it
口腔特别容易受伤害 the mouth is a specially vulnerable
但这里我们也全副武装，随时准备开火 here too we are armed and ready to fire
每一次喷出的唾液都含有“溶菌酶”（Lysozyme） each squirt of saliva contains Lysozyme
一种专门用来破坏细菌的酶 an enzyme specially targeted to destroy bacteria
唾液腺很小 our saliva glands are tiny
然而，他们每天产生将近半加仑（约1.5升，相当于一大瓶可乐）唾液 yet they produce nearly half a gallon of saliva every single day
有时，病原体（pathogen）冲破这些外部防御 sometimes, a pathogen break through these external defenses
我们还不成熟的免疫系统作出反应，以防止感染 and our immature immune system reacts to prevent infection
微小的病毒随我们的血液传播 tiny viruses travel through our blood
探测表皮细胞脆弱的迹象 and probe our skin cells for signs of weakness
病毒劫持一个细胞 the virus hijacks a cell
并在其内部制造成千上万的拷贝 and manufactures thousands of copies of it
之后，被感染的细胞破裂 then the infected cell ruptures
在体内传播更多的病毒 spreading even more viruses around the body
这次，这种特别的病毒会引起皮疹（rash） this particular virus causes a rash
水痘（chicken pox） chicken pox
而由感染带来的发热则是身体在反抗的迹象 the fever that comes with infection is a sign that the body is fighting back
热量减缓疾病的蔓延 heat slows down the spread of the disease
因为病毒在热的环境下不能很好的复制 because viruses don't reproduce well when its hot
所以免疫系统这时开始行动 the immune system kicks into action
白血球抓住被感染的细胞 white blood cells latch onto infected cells
注入有毒的蛋白质 and pump in poisonous proteins
杀死细胞的同时，也杀死病毒 which kills the cell and the viruses
硬壳皮肤疱疹是免疫系统 crusty skin blister signal the battle waved
和病毒斗争的信号 between the immune system and its viral ocellates xxx
每一个水泡都包含了细胞碎屑和数十万病毒残骸 each one contain cellular debris and the remains of a hundred thousand viruses
生病可能很不舒服，但是小时候得这样的病 it may be unpleasant. but getting diseases like this when we were young
对我们发育中的免疫系统而言是很重要的 is vital for our developing immune systems
我们的身体针对病毒制造有记忆能力的分子 Our bodies create memory molecules against the virus
称为“抗体”（Antiboides） Antibodies
过去，我们依靠来自母亲乳汁的抗体 We used to rely on antibodies from mother's milk
现在，我们可以自己做抗体了 Now, we make our own.
当我们年纪大的时候，如果再次得病 If we catch the same disease when we are older
抗体让我们能立刻识别出病毒 The antibodies enable our bodies to recognize the virus instantly
白血球将会在病毒复制前 white blood cells wipe it out
消灭病毒 before it has a chance to take order
这就是为什么童年是“接种疫苗”（Vaccination）的最佳时期 This is why childhood is the perfect time for Vaccination.
“疫苗”（Vaccines）是不足以造成伤害的剂量的病毒 Vaccines are harmless doses of viruses
比如“流行性腮腺炎”（Mumps）,“脊髓灰质炎”（Polio）和“风疹”（Rubella） like Mumps, Polio and Rubella
身体如同被真的感染过一样，能制造出抗体 The body creates antibodies, as if it had really been infected
现在，如果我们真正得病 now, if we ever catch the real thing
我们的身体就能识别并攻击病毒 the body will recognize it and attack
在生命的头十年，人体变化大得我们都认不出来 in its first decade, the human body changes beyond recognition.
但现在将出现的是身体最大的变化 but now comes the biggest change of them all
如同过山车一般的“青春期”（Puberty） the roller coaster ride of puberty
11岁 11 Years
十一岁时，对大多数人来说，青春期已经开始 By age 11, puberty is already under way for most
但这一过程没有具体的时刻表，有些人开始的晚些 but there is no schedule, for some it happens later
有些人早些 some earlier
这取决于我们的NDA时钟， it depends on our DNA clocks
我们的生活方式，甚至我们的饮食 our life styles even our diets
但是不论是10岁还是13岁 whether 10 or 13
男孩还是女孩 female or male
青春期都是从我们的脑部开始的 it begins in the brain for all of us
在大脑底部，下丘脑（hypothalamus）处 at the base, the hypothalamus
跟控制体温相同的区域 the same region that controls our body temperature
青春期是在下丘脑释放出一种蛋白质时开始的 puberty starts when the hypothalamus releases a protein
这种蛋白质称为 “Kisspeptin”，并将其注入大脑 注：Kisspeptin是一种肽类激素，2001年被发现，暂无译名 Kisspeptin into the brain
Kisspeptin 激活其他急速的释放 the Kisspeptin triggers the release of other hormones
在身体内造成连锁反应 in a chain reaction throughout the body
只有这时我们的性器官才开始成熟 only then do our sex organs begin to mature
对女孩而言，这意味着“排卵”（Ovulation） in girls, that means Ovulation
现在展示的是女性卵巢的高清晰度图像 this is a high definition view of a woman's ovaries
卵巢是位于中央高亮的灰白色的器官 the off-white organs in the center
这组独特的视频来自纽约的 Gold Coast IVF 养育中心 the unique footage from Gold Coast IVF fertility center in New York
展示出在保护疱液中的真实的卵子 shows an actual Egg inside a protective blister of fluid
在排卵时，一颗卵从卵巢破茧而出 during Ovulation, an egg burst from the Ovary
沿着“输卵管”（fallopian tube） and travels down the fallopian tube
下到“子宫”（Uterus） to the Uterus
从现在一直到“更年期”（Menopause） from now until Menopause
同样的事情每月都会发生 the same thing will happen every month
接下来，月经（Menstruation）排出子宫内未受精的卵子 then, Menstruation clears the Uterus of unfertilized eggs
卵巢不仅产生卵子，还能产生一组有效的化学物质 the Ovaries not only produce eggs, they also produce a potent cocktail of chemicals
他们将激素释放到血液中 they release hormones into the blood stream
包括“雌激素”（Estrogen） including Estrogen
这些激素有戏剧性持续情绪和身体的效果 these hormones have dramatic lasting emotional and physical effects
使得男孩和女孩出现“速长期”（Growth Spurt） both boys and girls experience a growth spurt
女人和男人的体型开始出现不同 women and men's body shapes diverge
17岁 17 Years
女孩变成了女人 girls become women
男孩也变成了男人 boys become men
男性的大脑也会释放出 Kisspeptin 来触发青春期 male brains also release Kisspeptin to trigger puberty
大量的新激素涌入睾丸（Testicles)，刺激产生精子 a flood of new hormone stimulates the testicles to produce sperm
睾丸还产生了睾酮（Testosterone）的10倍激增 the testicles also generate a 10-fold surge in testosterone
睾酮能够促进产生男性生理特征 the hormone that creates the physical characteristics of manhood
喉部（Larynx）张开，向前倾斜 the Larynx opens up and tilts forward
声带变宽 the vocal cord stretch wider
声带越长，声音震动的音调就越低 the longer chords vibrate at a lower pitch
声音就更低沉 the voice deepens
睾酮（睾丸激素）同时也刺激身毛生长 testosterone stimulates the growth body hair
并使肌肉质量倍增 and doubles muscle mass
这包括了增加40%的心脏肌肉 including 40% more heart muscle
这些是我们能看到和听到的变化 these are the changes we can see and hear
但是变化也在我们看不见的地方进行 but changes are going on that we can't see
大脑中，神经细胞正在进行大量的重排 in the brain, nerve cells undergo extensive re-wiring
转变我们的情绪和性格 transforming our mood and character
两性都体验到了众多新的情绪 both sex experiences are flood of new emotions
但其中之一最为强烈 and one beats them all
第一次 for the first time
两性都发现对方的性吸引力 both sexes find the other sexually attractive
从内到外，我们的身体都被这新感觉支配 from inside out, our bodies are overwhelmed by new sensations
脉搏加快 our pulse raises
血压升高 our blood pressure rises
嘴唇变得有光泽 our lips gorge
脸颊充血 our cheeks flush with blood
所有这些迹象表明，我们渴望某个人 all signs that we desire someone
如果这种渴望变成互相的 and if the desire turns out to be mutual
我们又达到了另一个重要的里程碑 we hit another major milestone
初吻 our first kiss
在生命的头20年里，人体的一些变化近似奇迹 in its first two decades the human body accomplish something close to miraculous
我们是原来的近4倍高 we are nearly 4 times our original height
21倍重 21 times heavier
我们已经消化了九千吨食物 we've digested 9 thousand tons of food
心脏跳动了超过十亿次 our hearts have beaten over 1 billion times
肺部呼吸超过两亿次 our lungs have drawn over 200 million breathes
现在，在青春期之后 now, with puberty behind us
我们在身体和精神上已经准备好 we are ready in mind and body
成为成年人 to become adults
在20岁出头的时候 our early 20s
童年和青春期已经在我们身后了 childhood and puberty are behind us
这是我们生命的一个新的阶段 this is the start of a new phase in our lives
成年期 adulthood
我们已经飞出鸟巢了。接下来的生活 we flown the nest. what happens now
已经完全取决于我们自己 is up to us
21岁 21 Years
二十多岁，我们的身体看上去，并且自己也感觉是一生中最好的时光 in our 20s, we look and feel better than that any other time in our lives
我们从内到外都处在全盛时期 we are in our prime both outside and in
万亿细胞组成器官和组织 trillions of cells make up of our organs and tissues
随着时间的推移，这些东西慢慢损坏 over time, these wear-out are get damaged
但是新的细胞生长分裂，代替旧的细胞 but new cells grow and divide to replace the old ones
身体已经替换了某些整个器官 our body replaces entire organs
所以难怪我们感觉良好 so it's no wonder we feel good
本质上说，每隔十年 essentially, every 10 years
我们就全部更新一次身体 we get a brand new body
有些组织甚至更新得更快 some tissue regenerate even faster
比如头发和指甲 like our hair and nails
这就需要我们常常光顾沙龙这样的地方 which requires a quick treat to the salon every so often
头发是死亡的皮肤细胞变成的 hairs are made from modified dead skin cells
每一根头发都是从嵌在皮肤中的“毛囊”（Follicle）长出来的 each hair grows from a Follicle embedded in the skin
构成头发的细胞在这里生长，由新的细胞向上推后死去 the modified cells grow here. and die as new cells push them upward
头发是死亡细胞组成的柱子 the column of dead cells is the hair
每个人每年能长出令人难以置信的 each person grows incredible 7 miles of hair
7英里（11公里）长的头发 every year
头发不论我们想不想，都在不停生长 our hair grows whether we wanted to or not
但身体的某些部分的生长则可以控制 but other parts of our body are partially under our control
现在做出的一些选择 choices we make now, like exercising
能影响到我们的余生，比如锻炼。 affected us for the rest of our lives.
这能影响我们全身 it has an effect throughout the body
帮助细胞和器官保持在巅峰状态 helping cells and organs stay in peak condition
肌肉也在生长 our muscles are also building
接下来要展示的是一种新技术，结合了高分辨率CT扫描 this is a new imaging technique that combines the highest resolution ct scans
和先进的电脑技术 with cutting-edge computer power
称为 Volumedic(R) it's called Volumedic(R)
它展示了组成我们身体重量三分之一的650块骨骼肌是什么样的 and it shows how our 650 skeleton muscles make up to a third of our adult body weight
有人说如果身体所有的肌肉一起工作 it's been suggested that if all the muscles in the body work together
他们能产生足够的力量提起超过11吨的重量，相当于四辆SUV车的重量 they would generate enough power to lift more than 11 tons. the weight of more than four SUVs
肌肉是由肌纤维束成 muscles are made from bundles of fibers
锻炼撕裂这些纤维 a good work-out rips these fibers apart
单细胞通过增加物质来修补损坏 but our cells repair the damage by adding extra material
所以肌肉长了回来，变得更大，更强壮 the muscle grows back. bigger and stronger
通过我们所做出的选择 through choices we made
不幸的是，有些选择是有害的 unfortunately, some choices are less beneficial
有一些损害我们身体无法修复 some exposes to damage that even our xxx cells cannot repair.
派对是20岁的生活的一部分 party is a part of life in our 20s
我们都知道吸烟会损害肺部 we all know smoke can damage the lungs
但这里，烟雾并不是唯一的危害 but smoke isn't the only hazard here
我们的听力也受到 our hearing is under threaten too
巨大噪声的危害 from loud noise
问题出在我们的耳内 the problem is deep inside the ear
耳蜗里脆弱的感觉毛发 the fragile sensory hairs in the cochlea
称为“纤毛”（stereocilia） were stereocilia
他们将声音转换为神经脉冲 turn sound into nerve impulses
巨大的噪声将破坏这些不可替代的细胞 loud noise destroys these irreplaceable cells
负责高频率声音的纤毛最容易被破坏 the hairs that respond to high frequencies are most effective
也许是因为高音震颤得更为剧烈 maybe because high pitch sound shake their foundations more violently
然而这些影响太小了而难以察觉 the effect is too small to notice
听力范围却已经在缩小 but the frequency range of our hearing is already shrinking
另一个危害的来源是酒精 another source of damage is alcohol
当我们将酒精吸收到血液中时 as we absorb alcohol into our blood stream
酒精同时影响我们的神智和器官 it both affects our organs and our state of mind
它使血压升高 it raises our blood pressure
让心脏跳动不规律 and makes our heart beat irregular
我们放松，失去抑制力 we relax, lose our inhibitions
以及协调能力 and our coordination
这些症状是由于脑中的化学反应 these symptoms are consequence of chemical reactions in the brain
特别是在这一区域，小脑（Cerebellum） especially in this region -- the Cerebellum
小脑控制协调能力和平衡 it controls coordination and balance
喝酒时，酒精影响小脑细胞 when we drink, alcohol affects the cerebellum's brain cells
脑中部分突触更为频繁的接收信号 some synapses accept the signal more frequently
其他的则完全失效 others become totally blocked
喝得越多，影响越明显 the more we drink, the more extremely effect
现在可能感觉很好 it may feel good now
但接下来就要付出代价 but there will be a price to pay later
在派对过后 after a party
随着时间的推移，我们逐渐了解我们的极限 time passes, and we get to know our limits
现在，新的挑战出现了 now new challenges are around the arisen
寻觅爱情 to find love
并且养育后代 and have children of our own
我们近三十岁时 our late 20s
童年已经成为遥远的记忆 childhood is a distant memory
但初吻并不遥远 but not the thriller of our first kiss
这是纯粹的欲望 that was pure lust
现在到了接受一些新的东西的时候了 now it's time for something new
到了爱上某人的时候了 it's time to fall in love
28岁 28 years
我们中的大多数在工作场合遇见另一半 many of us meet our future partners at work
你也许认为吸引力是社会或身体的 we may think the attraction is social or physical
但其实大部分却是生物的 but a lot of it is biological
我们用眼睛来打量对象 we use our eyes to size up our date
但视觉并不是所有 but looks aren't everything
吸引力同时也需要嗅觉 attraction is also about smell
鼻腔内部 inside the nose
嗅觉（olfactory）神经的作用不仅仅是检测味道 olfactory nerves do more than detect smells
他们还能检测我们闻不到的化学物质 they also detect chemicals we can't smell
信息素（pheromones）是一种无味的激素讯息 pheromones, odorless hormonal messages
我们在汗液中释放 we release in our sweat
信息素承载有关于遗传健康的信息 pheromones carry information about our genetic health
并且能告知我们抵抗疾病的能力 and our ability to resist disease
大脑利用了这些信号 our brains use these signals
来帮助我们选择未来的伴侣 to help choose a partner
其必须携带有能给后代最好的基因 with the best possible genes for our children
爱情不仅仅是一种感情 love is more than just emotion
它完全就是化学 it's all about chemistry
肾上腺素（adrenalin）进入血液 we release adrenalin into the blood
我们的心里已经小鹿乱撞（心跳得厉害） our heart pounce
无法入睡 we can't sleep
（晚上八点见） meet at 8 pm
当这种情况发生时，另一种激素发挥作用 when that happens, another hormone comes into play
大脑中充满了“多巴胺”（dopamine） the brain floods with dopamine
让人感觉良好的激素 the feel good hormone
这种激素跟可卡因一样强大 it's as potent as cocaine
让我们感到愉悦，并且上瘾 makes us jovial and it's addictive
他让我们希望得到更多 it leaves us wanting more
我们开始考虑承诺 we start thinking about commitment
并最终结婚 and eventually marriage
爱情，既是化学的也是感情的 love, both chemical and emotional
在这一天赢得胜利 wins the day
这是一种我们希望持续终身的关系 it's a relationship we hope will last all lifetime
并且是一条长期接合的路 and the paths of long term bonding
这是化学的 is chemical
性不仅仅是繁衍 sex isn't just about procreation
或娱乐 or recreation
性从化学的角度加强了我们之间的关系 it chemically strengthens the bond between us
性爱双方的“脑垂体”（pituitary glands）输送 both partner's pituitary glands pump
给血液大量称之为“催产素”（Oxytocin） the blood full of the substance called
的物质 oxytocin
有时，这又被称作“结合激素” sometimes called the bonding hormone
这和我们出生时连结我们和母亲的激素是同一种 it's the very same hormone that binds us to our mothers as new borns
一些人类学家相信 some anthropologists believe
催产素是由进化而来的一种让我们结合的手段 oxytocin could be evolution's way of creating a bond
它强大到能够让我们承受为人父母的尝试 that strong enough to endure the trials of parenthood
成为父母的时机就是现在 and the time for parenthood is now
男人释放精子 the man releases sperm
目标是找到卵子 the goal to find the egg
一颗卵子在女人的卵巢成熟，脱落 an egg ripens and birth from the women's ovary
卵子是人体中最大的细胞 the largest cell in the human body
它经过输卵管（Fallopian tube） it passes into the Fallopian tube
准备好了受孕 ready for fertilization
精子是人体最小的细胞 sperm are the smallest cells in the human body
在他们面前的是一条艰辛的道路 and they have a tough journey ahead of them
首先，他们必须在阴道险恶的环境中生存 first they have to survive the hostile environment of the vagina
阴道的分泌物是酸性的，以防止细菌感染 it's secretions are acidic to prevent bacteria infection
并且也会杀死精子 but they also kill sperm
射精（ejaculation）能释放出三亿个精子 ejaculation releases 300 million sperm
但只有几千个可以到达“子宫颈”（Cervix） but only thousands will make it as far as the Cervix
幸存的精子游入子宫和输卵管 the surviving sperm swim into the uterus and fallopian tube
输卵管壁肌肉收缩 muscular contractions in the walls of fallopian tube
帮助指引精子游向卵子 help guide the sperm toward the egg
只有几百个能到这么远 only a few hundred make it this far
而只有一个能让卵子受孕 and only one will succeed in fertilizing the egg
这真正是“适者生存”（survival of the fittest） this truly is survival of the fittest
10小时后，三亿精子中最强壮的那一个 10 hours later, the strongest of 300 million sperm
将能够延续他所携带的基因 is the one to pass on its genes
到目前为止，人体还没有任何受孕的反应 so far, there is no sign of conception
我们还不知道我们将要开始步入人生的一个新篇章 we are totally unaware that we are about to unbark on a new chapter in our lives
在接下来的40周里 over the next 40 weeks
一个单细胞会发育成一个完全成形的 a single cell will develop into a perfectly formed
婴儿 baby
第一个症状常常是孕吐（妊娠反应） often the first symptom is morning sickness
没有人准确地知道导致呕吐的原因 no one knows for sure what causes the nausea
有一种说法是呕吐可以在发育的关键时机 one theory is that it protects the fetus from toxins in food
让胎儿避免遭到食物中 which could harm its organs
会损伤婴儿器官的有毒物质的侵害 during this critical phase of development
另一中说法是说呕吐是母体免疫系统的一种副作用 another theory is that nausea is a side effect of the mother's immune system
因为母体变得虚弱，就能避免其攻击发育中的胚胎 as it weakens to avoid attacking the developing embryo
实际上胎儿就像是一个寄生虫 the fetus is effectively a parasite
在它从母体中吸收所需的的营养，消耗母亲的能量 it saps the mother's energy as it draws what it needs from her body
胎儿有它自己的生命维持系统 it has its own life support system
胎盘（Placenta） the placenta
在这里，母亲的血液会流经一个薄膜然后把营养物带进胎儿的血液中 here, the mother's blood passes nutrients across a membrane into the fetal blood
随着食物的不断供应 with its constant supply of nourishment
在第一个十周内，胎儿能发育到超过30盎司（850克） the fetus grows over 30 ounces in its first 10 weeks
子宫要增大到原来大小的一千倍 the uterus expends to 1000 times its normal size
仅仅只是为了支撑胎儿 just to hold it
那么额外的空间肯定是来至一些地方 that extra space has to come from somewhere
所以母体会在内部做重新的调整 so the mother's body rearranges itself internally
这个女人没有怀孕 this woman isn't pregnant
但是她的器官仍然很密集 but her organs are still a tight fit
在怀孕女人的体内 in a pregnant woman
器官会被挤压 the organs get squeezed
有的会被推挤到胸部 and some are pushed up into her chest
不仅器官会被挤压 not only are the organs squashed
而且他们还要为两个人工作 now they are working for two
肺和心脏会工作地比以前更幸苦 the lungs and the heart work harder than ever before
为了争取空间，脊柱的肌肉和肌腱（tendon） to make space, muscles and tendons in the spin relax
并且弯曲变形 and it curves out of its normal shape
胃也会被挤压 the stomach is also compressed
同时被旋转成45度 and rotated through 45 degrees
它只能承受住少量的食物和水 it can only hold small amounts of food and drink
但是逐渐长大的婴儿却需要更多食物 and still the growing baby demands more
9个月以后就进入了分娩的时期 after 9 months, its time to give birth
而生出一个7磅（3公斤）的婴儿是相当具有挑战性的 and pushing out a 7 pound baby can be quite a challenge
变软的肌腱会让骨盆（Pelvis）打开产道（birth canal） soften tendons allow the pelvis to open up the birth canal
但尽管如此，空间仍然很拥挤 but even so, it's a crowd space
Volumedic 图像技术展示了婴儿出生时要经过的路线 volumedic imagine shows the claustrophobic route the baby has to take
有一些卷曲的到达尾骨 with a tight twist to get around the tail bone
有时对于母婴而言产道太紧了 sometimes it's too tight of a squeeze for mother and baby
这时，唯一安全生产的方式就是手术 the only option for a safe delivery is surgery
剖腹产（Caesarean section） a Caesarean section
从一个新生儿，到成为父母的30年里 from a new born baby to becoming a parent in 30 years
生命之圈还在继续 the circle of life goes on
20岁已经离我们远去，身体将要开始一个新的变化时期 our 20s are behind us. our bodies are about to enter a new period of change
这就是衰老 as the aging process
的开始 takes on
有些专家认为，我们自出生起就开始了衰老 some experts believe that we all start aging from the moment we are born
身体的修复系统补偿了这一过程 the body's repair systems compensate
但现在，修复系统本身开始老化 but now, the repair systems themselves are aging
我们外表的变化越来越明显 the changes in our appearances are getting noticeable
我们进入了40岁 we are in our 40s
45岁 45 Years
年龄和阳光日积月累的影响下 the accumulative effect of years and the sun
出现了第一个症状（Symptom） causes the first symptom
皱纹（wrinkles） wrinkles
从出生开始，我们的皮肤细胞就已以惊人的速度补充我们的皮肤细胞 since birth, our skin cells have replenished our skin at an astonishing rate
我们每分钟最多可以生成三万个新的皮肤细胞 we can make up to 30 thousand new skin cells every minute
以替代不断脱落的死亡细胞 to replace the dead cells where constantly shedding
45岁时，我们累积已经制造了超过400磅（180公斤）的皮肤碎屑 by 45, we've created more than 400 pounds of dust from old skin cells
不论我们几岁，皮肤细胞都不会超过几个月的年龄 whatever our age, our skin cells are never more than a few months old
皮肤细胞没有什么问题 the skin cells are fine
问题出在将皮肤细胞结合在一起的东西 the problem is the stuff that binds them together
胶原蛋白（collagen） collagen
来自太阳的紫外线光辐射 ultraviolet radiation in sun light
引发了分子间的链式反应 triggers a molecular chain reaction
这种反应能降解胶原蛋白 that degrades collagen
使得纤维越来越薄，断裂 the fibers get thin and break
皮肤失去弹性 our skin loses elasticity
于是产生皱纹 and we get wrinkles
视力也在改变 our eye sight is also changing
几年前，我们不带眼镜仍能轻易的阅读 a few years ago we can easily read without glasses
现在，晶状体（lens）出问题了 the problem is in the lens
晶状体内的细胞，心脏细胞以及大部分的脑细胞 inner lens cells, along with heart cells and most brain cells
是身体唯一从不替换的的细胞 are among the only cells our bodies never replace
晶状体跟我们出生时的晶状体完全一样 they are exactly the same lens cells as we had as babies
当我们变老时，晶状体逐渐变硬 as we get older, the lens is gradually stiffen
他们不能很好的对焦了 they don't focus as well
眼睛也开始变的干燥 and our eyes start to dry out
用来润滑眼睛的液体越来越少 we produce less fluid to lubricate the eye
越来越少的眼泪来冲走残骸 and fewer tears to flush out debris
中年的我们，体型也在发生改变 middle age also changes the shape of our bodies
运动本身已经无法再让我们保持体型了 exercise alone isn't enough to keep us in shape anymore
20岁时，保持体型很容易 at 20, it was easy
我们吃多少都没关系，做什么也都没关系 we can eat what we wanted, do what we wanted
但现在，新陈代谢（metabolism）发生了改变，变得更容易变胖 now our metabolism is changed, and it's easier to put on weight
原因在血液 the explanation is in our blood
中年时，多种激素水平下降 in middle age, the level of several hormone start to drop
雌激素（estrogen），睾酮（testosterone）和生长激素（growth hormones） estrogen, testosterone and growth hormones
我们开始失去四肢的肌肉 and we start to lose limb muscle
成年期的我们每十年减少大约6.5磅（3公斤）的肌肉 we lose about 6.5 pounds of muscle during each decade of our adult lives
肌肉越少，身体消耗的热量就越少 less muscle means the body burns fewer calories
于是我们不需要那么多的燃料了 we need less fuel
如果我们还像以前那样吃下去的话 if we continue to eat like we used to
过剩的食物就会转换成这样 the surplus food gets converted into this
脂肪 fat
对女人而言，脂肪往往聚集在臀部 for women, fat tends to go to their hips
这是身体的一种怀孕时供应稳定能量的方式 it's the body's way of providing a steady energy supply for pregnancy
而男人将脂肪累积在不同的地方 man store fat in a different area
腰部 their bellies
腰部脂肪进化成能快速释放能量 belly fat evolve for quick energy release
这帮助我们的男性祖先能在狩猎旅行中生存下来 it help sustain our male ancestors during hunting trips
然而脂肪代谢的能力随着年龄而减慢 our ability to metabolize fat slows down as we age
在体内的每个细胞中，都存在着一种微结构称为“线粒体”（Mitochondria） inside each cell in our bodies, there are tiny structures called Mitochondria
这些线粒体是我们身体的发电厂 these are the bodies' power plants
他们将食物里的营养物质 they combine nutrients from food
和肺部来的氧气结合 with oxygen from the lungs
以释放能量 to release energy
当我们逐渐老去 as we get older
线粒体的数量逐渐变少 the number of mitochondria dwindles
我们越来越不能有效地代谢脂肪 and we lose the ability to metabolize fat as efficiently
过多的热量摄入加上代谢率的降低 too many calories and the drop in metabolic rate
构成了致命的组合 can be a lethal combination
脂肪远远不只是我们腰部的赘肉 fat is much more than an extra insure on our waist line xxx
它还是整个身体的粮食 it's bread throughout the entire body
首次 for the first time
借由高清晰度内窥镜 a high-definition endoscope
从肚脐插入 inserted through the navel
在腹部 reveals the folic ***(stent) of fat cover
揭示了脂肪的覆盖 inside the abdomen
肠道被黄色的脂肪沉积包裹 the intestines are smothered in yellow fat deposits
脂肪能进入我们体内几乎任何可用的空间 fat finds its way into almost every available space of our bodies
甚至进入到血管内 even inside of our blood vessels
沉积在血管内壁 deposits build up on the inner walls
缩小了血管 narrowing the tube
心脏就必须加倍努力输送血液 the heart has to work harder to pump blood
以通过狭窄的血管 through the restricted vessels
在某些极端情况下 in extreme cases
脂肪甚至可以彻底阻塞血管 fat can block the vessels completely
如果脂肪阻塞了给心脏供氧的动脉 if fat blocks the arteries that supply the heart
结果将是致命的 the result can be fatal
心肌被剥夺了氧气和养分 the heart muscles are deprived of oxygen and nutrients
有痉挛的危险 the muscle risks going into spasm
导致心脏病发作 a heart attack
心脏病是西方世界最大的杀手 heart disease is the biggest killer in the western world
脂肪并不是我们衰老时的唯一危险 fat isn't the only risk to our health as we age
压力也起着破坏性的作用 stress also plays a damaging role
中年生活充满压力 middle age life is stressful
稳住工作并且抚养青少年的子女 holding down the job and raising teenage kids
压力让人精疲力尽 stress is exhausting
但破坏却不停止 but the damage doesn't stop there
甚至加快了衰老 it also speeds up the aging process
50岁 50 years old
我们的身体可能变慢了 our bodies maybe slowing down
但我们的生活节奏却没有 but our life styles aren't
日趋庞大的家庭，以及艰巨的事业 a growing family and a demanding career
这些加起来成为另一个影响衰老过程的因素 add up to another influence on the aging process
这就是压力 stress
50岁 50 years
我们都认得压力的外在表现 we all recognize the outward signs of stress
手心出汗，呼吸急促 sweaty palms, shortness of breath
晕眩的感觉 a dizzy feeling
然而真正的损害发生在身体内部 but the real damage takes place inside
我们的身体本能的转变到“战或逃”的状态 our bodies instinctively shift into fight or flight mode
激素，肾上腺素和皮质醇从肾上腺涌出 hormones, adrenalin and cortisol flood from the adrenal gland
进入血液 into our blood stream
这时我们的肌肉收缩 our muscles contract
动脉紧缩 arteries constrict
心跳变得更快 the heart pumps faster
血压达到极限 and our blood pressure hits the roof
我们演化出“战或逃”的反射 we evolve the fight or flight reflex
以快速响应捕食者的袭击 to quickly respond to attacks from predators
但太经常出发这种反射 to have the reflex triggering so constantly
会对我们的心血管网造成不可挽回的伤害 causes irreparable harm to our cardial vascular network
压力加速血管的老化 stress accelerates the aging of our blood vessels
高血压损害动脉壁的细胞 high blood pressure damages cell in the artery walls
使其变得坚硬并且变厚 they become stiff and thick
特别是在人体最大的动脉 especially here in the biggest artery
主动脉（aorta） the aorta
动脉壁僵硬限制了血液流速 arteries with stiff walls restrict blood flow
使血压升高 as our blood pressure raises
心脏不得不更加努力的工作 the heart is forced to work harder
这是一个恶性循环。我们得到的压力越多 it's a vicious cycle. the more stress we get,
对血管的破坏就越大 the more we damage our blood vessels
而对血管的破坏越大 and the more we damage our blood vessels,
我们就越难对付压力 the less we are able to deal with the effects of stress
如果问题超出我们的控制 if the problem gets out of control
心脏就会增大 the heart becomes enlarged
以应对输送血液通过狭窄 as it struggles to force blood through our narrow
缺少弹性的血管的情况 less elastic blood vessels
高血压最终能让大脑中的血管破裂 high blood pressure can even rupture blood vessels in the brain
造成中风（Stroke） a stroke
但我们中的大多数都知道如何控制压力 most of us learned to manage stress
但对于50岁的女人 but for women in their 50s
另一个因素加重了问题 another factor compounds the problem
停经（Menopause） Menopause
50岁时，女性的卵巢停止释放卵子 in their 50s, a woman's ovary stop releasing eggs
同时也停止产生性激素 they also stop producing sex hormones
包括“雌激素”（estrogen）和“孕酮”（progesterone） estrogen and progesterone
这标志着女性生育生活的结束 which signals the end of a woman's reproductive live
随着激素供应的下降 as the supply of hormones xxx down
大脑负责处理情绪，睡眠和温度控制的区域 it destabilizes the regions of the brain that deal with mood
开始变得不稳定 sleep and temperature control
当下丘脑偏离航线 when the hypothalamus is thrown off course
潮热就发生了 hot flash is occurred
这时，身体不能将体温控制到正确的位置 moments when the body can't set its thermostat correctly
骨骼和肌肉组织变弱 bone and muscle tissues weaken
女人的身体一辈子都在适应这些激素 the woman's body has spend its whole life getting accustom to these hormone
但现在他们突然不见了 now they are gone
老龄化进程加快了 and the aging process accelerates
我们的六十岁来了又走 our 60s come and go
我们的孩子离开家 our kids leave home
我们也离开了工作岗位 and we leave work
从此进入了生活的一个新的阶段 we enter a new phase of life
老年 old age
在70年里 in 70 years
我们从一个小宝宝 we've grown from a tiny baby
长成成年人 to an adult
从孩子到父母 from child to parent
再到祖父母 to grandparent
老龄化进程始于几十年前 the aging process began several decades ago
现在我们已经到了老年期 now we are in the grip of old age
这是生命旅程的最后一章 it's the final chapter in the journey of life
退休以后，我们的生活方式日趋缓慢 when we retire from work, we gain a slower life style
我们的身体也慢了下来 and our body slow down
外表的老化只是开始 the outwards signs of aging are only the beginning
衰老同时也极大的影响我们的骨骼 aging also dramatically affects our skeletons
我们中的任何人都有可能患上“骨质疏松症”（osteoporosis） any of us could be at risk for osteoporosis
我们的骨细胞仍在辛勤工作 our bone cells are still hard work
破坏旧的骨骼，换上新的 destroying old bone. and replacing it with new
然而，年老的我们这一平衡已被打乱 but old age upsets this balance
“破骨细胞”（osteoclast）过快的破坏骨头 以至于“造骨细胞”（osteoblast）来不及重建 osteoclast destroy the bone faster than osteoblast can rebuild it
留下的就只剩空心而脆的骨纤维簇 what remains is a hollowed out cluster of brittle bone fibers
我们的骨头慢慢的变碎 our bone slowly crumble
随着时间的推移 as the year slide by
骨折的危险变得极为现实 broken bones become a very real danger
男人和女人都有可能发生 it can happen to men and women alike
然而在女人身上，这个过程比男人要快 but the process is faster in women
这是由于停经造成的激素变化 because of the hormonal changes of menopause
衰老的过程是最伟大的生命之谜之一 the aging process is one of the great mysteries of life
为什么我们的外貌变化如此之大 why does our appearance change so much
在40到70岁之间 between the ages of 40 and 70
这已远超过磨损 it's more than wear and tear
这是一个影响身体里每个细胞的过程 it's a process affecting every cell in our bodies
每天，细胞克隆数十亿个 every day, cells clone themselves into billions
来应对身体器官的磨损 to battle wear and tear on our organs
每个细胞内的DNA都被复制了 the DNA inside each cell gets copied
老的细胞死去 the old cells die off
新的细胞替代了他们的位置 and the new ones take their place
然而这个复制系统并不是完美的 but the copying system isn't perfect
DNA中的任何缺陷 any imperfections in our DNA
都被复制了下来 are also duplicated
在我们的一生中，我们复制了多个自我 over our lifetime, we make so many copies of ourselves
使得最细小的缺陷也被累积 that even the tiniest defects accumulate
这就像复印机 it's like using a photo copier
从复印件复印来的复印件质量就会下降 copies made from copies degrade in quality
从出生起，每隔十年，我们就完全替换一次脸部的骨骼 we have totally replaced the bone in our face every 10 years since we were born
我们70岁的脸已经是第七代副本 our 70-year-old face is a 7 generation copy
从婴孩时期的脸复制而来 of our baby face
缺陷在每一次复制都被扩大 the imperfections are exaggerated with each copy
另一个原因，可能是因为我们所呼吸的空气 another reason for aging could be the air that we breath
我们需要氧气来存活 we need oxygen to live
但在一生中 but throughout our lives
氧气却缓慢的毒害我们 it's slowly poisons us
在每个细胞内 inside each of our cells
“线粒体”（mitochondria）就像微小的发电厂 our mitochondria are like tiny power plants
将食物与氧气结合 combining food with oxygen
线粒体制造出我们需要的能量 they create the energy we need
但就如发电厂，他们也产生污染 but just like a power plant, they also generate pollution
在这里，这种污染就是氧气 in this case, the pollutant is oxygen
线粒体将分子变成不稳定的形式，称为“自由基”（free radical） the mitochondria change molecules into unstable forms called free radical
一生中，自由基缓慢的使线粒体窒息 over our life time, free radical slowly suffocate the mitochondria
并破坏细胞 and damage our cells
我们的细胞和DNA被损坏的越来越厉害 our cells and DNA become more and more damaged
以至于修复系统失效 repair systems fail
缺陷被累积 imperfections accumulate
最终，器官失效 eventually, our organs fail
哪怕你的生活方式很健康 even with a healthy life style
并且有良好的药物治疗 and the best medicine
死亡也是不可避免的 death is unavoidable
DNA决定了我们是谁 our DNA makes us what we are
并指引我们发育 and guides our development
然而它也决定了我们能活多久 but it also determines how long we live
每一次细胞复制自己的时候 every time one of our cells copies itself
就丢失其DNA尾端很小的一块 it loses a tiny piece from the end of the DNA
经过数十亿次的分裂 after billions of self divisions
整个尾端都消失了 the end section is gone
这时细胞不能再次分裂 our cells can't divide anymore
死亡，如同生活，也是一个生物过程 death, like life, is a biological process
科学家认为，接近死亡的时刻 scientist believe that near the moment of death
我们的血液中弥漫着内啡肽（Endorphin） our blood stream is flooded with endorphins
如同之前说过，内啡肽是自然的止痛药 the bodys natural pain killers
现在，由于缺氧 now, starved of oxygen
身体组织无法运作 tissues can't function
在十秒内，大脑的电活动骤降 within 10 seconds, the brain's electrical activity drops
听觉是最后一个消失的感官 hearing is the last sense to go
可能需要一天，皮肤细胞才会停止分裂 it can take 24 hours for our skin cells to stop dividing
最后的电脉冲 its final impulse
有一种说法是，生命还会继续 there's a saying that life goes on
但对我们中的一些人来说，生命的确能继续一段时间 for some of us, it could go on for some time
感谢现代医药的帮助 thanks to modern medicine
现今在美国出生的孩子 children born in the US today
将有可能活到庆祝他们77岁生日的时候 can expect to live to celebrate their 77th birthday
甚至更久 and beyond
甚至当我们过世后，我们的生活也能通过亲人 even when we are gone, we live on through loved ones
我们的孩子和他们的孩子，他们的每一个细胞都带有我们的基因 our children, and their children carry our genes in every cell
他们带有我们的记忆 they carry memories of us too
这些记忆就是他们与我们共享的，我们生命非凡的故事的一幕又一幕 the moments they've shared from our extraordinary story
所有的旅行都有尽头，天下没有不散的筵席 all journeys must come to an end
但回头看看，这是怎样的一个旅程啊！ but what a journey it's been
感谢收看 欢迎给字幕纠错 =Ryan= 安勤 全程听译 biogerm from VeryCD http://biogerm.cn/ http://pics.biogerm.cn/ 献给我爱的人 thanks for watching =Ryan= biogerm from VeryCD http://biogerm.cn/ http://pics.biogerm.cn/ to my loved ones