Why do we cry? The three types of tears - Alex Gendler

我们为什么哭? 眼泪的三种类型 - 阿里克斯 简德乐

翻译人员: Wenbo Li 校对人员: Keke Gu

Our story is about a girl named Iris.

我们的故事是关于一个名叫虹膜的女孩.

Iris is very sensitive.

虹膜很敏感。

(Bird cawing)

So much that she is always in tears.

以至于总是以泪洗面。

She cries when she's sad,

她难过的时候会哭，

when she's happy,

她开心的时候也会哭，

(Godzilla roars)

and even tears up when things just get to her.

甚至被惹恼了，还是会哭。

She has special lacrimal glands to make new tears

她特殊的泪腺可以分泌新的泪水，

and special tubes, called lacrimal puncta,

还有特殊的管道，叫做泪道，

to drain old ones away.

用来排走眼泪。

And she cries so much that she goes through

她哭得很厉害，

ten ounces of tears per day,

每天会流掉十盎司的泪水， （注：盎司，重量单位，1盎司相当28.35克。）

thirty gallons a year!

一年三十加仑！ （注：加仑，容积单位，1加仑大约4L）

In fact, if you look closely,

事实上，如果你仔细观察，

you'll see that she's crying a little bit all the time.

你会发现她无时不刻都流点眼泪。

The basal tears that Iris constantly produces

虹膜不断产生一点基底眼泪

form a thin coating of three layers

形成薄薄的三层外膜

that cover her and keep dirt and debris away.

以防止她接触灰尘、碎屑。

Right next to Iris is the mucus layer,

紧挨着虹膜外面的是粘液层。

which keeps the whole thing fastened to her.

给她固定整个组织。

On top of it is the aqueous layer,

在她上面的是眼房水层，

which keeps Iris hydrated, repels invasive bacteria,

用来保持虹膜湿润，

排斥侵入性细菌，

and protects her skin, or cornea, from damage.

并保护她的皮肤，也叫角膜，保护她免受侵害。

And, finally, there is the lipid layer,

并且，最后，还有脂质层，

an oily outer film that keeps the surface smooth

一层保持表面平滑的油性外膜

for Iris to see through,

方便虹膜透视

and prevents the other layers from evaporating.

也防止其他层的蒸发。

通常情况下，虹膜整天

Normally, Iris goes about her day

without really noticing the basal tears doing their thing.

也没有注意过基底眼泪

在默默的工作。

That's kind of their whole point.

某种程度上说，这是它们的存在价值。

But one day, she meets a girl named Onion.

直到有一天，她遇到了一个叫做“洋葱”的女孩。

Iris is immediately smitten.

虹膜倍受打击。

Onion looks gorgeous in her bright purple jacket,

洋葱在她明亮的紫色外套的烘托下看起来很华丽

and she smells terrific.

并且闻起来棒极了。

So, Iris invites Onion to her house for dinner.

于是，虹膜邀请洋葱来家里吃晚餐，

当洋葱进屋，并且脱下外套，

But when she comes in and takes off her jacket,

something terrible happens.

可怕的事情发生了，

You see, when Onion's jacket is removed,

你看，当洋葱脱下外套，

a chemical reaction happens,

一个化学反应发生了，

converting the sulfoxides that make her smell so great

把让她闻起来有浓烈味道的亚砜，

into sulfenic acid,

转化成次磺酸，

which then becomes a nasty substance with a long name:

进而变成一个有巨长名字的讨厌的物质：

syn-Propanethial S-oxide.

丙硫醛-S-氧化物。

这种气体刺激着虹膜，

The gas stings Iris, and suddenly, she can't help it,

来势汹汹，她无力阻止，

she starts weeping uncontrollably.

于是她开始控制不住地大哭。

These reflex tears are different from the basal tears

这种反应性的眼泪与虹膜经常流的

that Iris is used to.

基底眼泪不同。

Because they're designed

因为，它们是为了

to wash away harmful substances, or particles,

冲掉有害的物质或颗粒。

它们的流量更大，

they're released in much larger amounts,

and their aqueous layer contains more antibodies

并且水层中包含大量抗体

to stop any microorganisms that may be trying to get in, as well.

也为了阻止可能进入眼睛的微生物。

Both Iris and Onion are devastated.

虹膜和洋葱都震惊了。

They know they can't continue their relationship

她们知道将无法继续做好朋友了

如果虹膜会受到伤害和哭泣

if Iris is going to hurt and cry every time Onion takes off her jacket.

在每次洋葱脱下外套的时候。

So, they decide to break up.

于是，她们决定绝交。

As Onion walks out the door, Iris stops crying.

当洋葱走出房门时，

虹膜停止了哭泣，

And immediately starts again.

紧接着她又开始哭，

Only now, she's not crying reflex tears but emotional tears.

但是这次，她并不是反射性流泪，

而是动情落泪。

When someone is either too sad or too happy,

当一个人太难过或是太开心的时候，

it feels like a loss of control,

就会感到失控

which can be dangerous.

这是很危险的。

So, emotional tears are sent in to stabilize the mood

因此，留下动情的泪水可以

稳定情绪，

as quickly as possible,

尽快地，

along with other physical reactions,

和其他物理反应一起作用，

such as an increased heart rate and slower breathing.

比如加快心率

和减缓呼吸。

But scientists still aren't sure

但是科学家们仍无法确定

exactly how or why the tears themselves are helpful.

眼泪是为什么或如何起到效用的。

They may be a social mechanism to elicit sympathy or show submission.

可能是一种社会机制

来博取同情，或者表达意见。

But some studies have also found

但是某些研究也发现

that emotional tears contain higher levels of stress hormones,

动情留下的泪水中包含较高浓度的

应激激素，

such as ACTH and enkephalin,

比如促肾上腺皮质激素和脑啡肽，

an endorphin and natural pain killer.

一种内啡肽，可以自然止痛。

In this case, emotional tears are also directly calming Iris down,

在这种情况下，情感泪水也可以让虹膜冷静下来，

as well as signaling her emotional state to others.

以及向别人传递她的情绪，

Sorry things didn't work out with Onion, Iris,

很抱歉，虹膜，你不能和洋葱做朋友了，

but don't worry.

但是别担心，

As long as you have all three kinds of tears

只要你拥有这三种泪水

working to keep you balanced and healthy, it will get better.

来保持你的健康均衡，

一切都会好起来。

You'll see.

你会看到的。