你的大脑喝了咖啡后会怎样：英语精读讲义

With its stimulating effects, 語法

凭借提神醒脑的效果，

it's easy to understand why coffee is the second most traded commodity 語法

不难理解为什么咖啡是全球交易量第二大的商品，

on Earth after oil.

仅次于石油。

For many,

对许多人来说，

it keeps us awake 語法

它让我们保持清醒，

and moving through our busy days.

并支撑我们度过忙碌的一天。

But how does it work?

但它是怎么起作用的？

What exactly does coffee do to your brain?

咖啡究竟会对你的大脑产生什么影响？

Whenever you're awake,

每当你醒着时，

a chemical called adenosine 語法

一种叫作腺苷的化学物质

slowly accumulates in your brain.

就会在大脑中慢慢积聚。

And this adenosine binds to receptors,

腺苷会与受体结合，

which slow down brain activity.

从而减缓大脑活动。

Ultimately, the more adenosine there is, 語法

归根结底，腺苷越多，

the more tired your brain feels,

你的大脑就越觉得疲倦。

which makes sense as the longer you're awake,

这很好理解，因为你醒着的时间越长，

the more fatigued you become.

就会越疲惫。

Conversely, while you sleep,

相反，在你睡觉时，

the concentration of adenosine declines,

腺苷的浓度会下降，

gradually promoting wakefulness.

让你逐渐恢复清醒。

But it turns out that the caffeine in your coffee 短語搭配

但事实证明，咖啡中的咖啡因

is incredibly similar to adenosine in structure. 短語搭配

在结构上与腺苷极其相似。

The caffeine works its way through your bloodstream 習語

咖啡因会随着血液循环

and into your brain,

进入你的大脑，

where it starts to compete

并在那里开始竞争，

and binds with the adenosine receptors.

与腺苷受体结合。

But because it's not adenosine,

但由于它并不是腺苷，

the sleepiness effect isn't felt.

所以不会产生困倦感。

Adenosine can no longer bind,

腺苷无法再与受体结合，

meaning its calming properties are diminished, 語法

这意味着它的镇静作用减弱了，

which is great for you when you're feeling tired.

对疲惫时的你来说，这可太好了。

However, with long-term use of caffeine,

然而，长期摄入咖啡因后，

your brain responds by creating more adenosine receptors,

你的大脑会制造更多腺苷受体来应对，

which means more caffeine is required

这意味着你需要摄入更多咖啡因，

to elicit the same response. 短語搭配

才能获得同样的效果。

It also means that when you try to quit drinking coffee 語法

这也意味着，当你试图戒掉咖啡

or miss your daily intake,

或漏掉每天那一杯时，

you might experience some withdrawal symptoms 用詞

你可能会出现一些戒断症状，

and feel more tired than you would have 語法

而且会觉得自己比

before you ever drank coffee.

从未喝过咖啡时更加疲倦。

But the caffeine doesn't stop there. 習語

但咖啡因的作用还不止于此。

It also stimulates the production of adrenaline,

它还会刺激肾上腺素的分泌，

you know, the fight or flight hormone. 用詞

没错，就是引发“战斗或逃跑”反应的激素。

This increases your heart rate,

这会加快你的心率，

gets your blood pumping, 習語

促进血液循环，

and even opens up your airways. 短語動詞

甚至扩张呼吸道。

Furthermore, it affects dopamine levels

此外，它还会影响多巴胺水平，

by preventing its reabsorption in the brain,

阻止大脑重新吸收多巴胺，

which makes you feel happy.

从而让你感到愉悦。

In fact, this is the exact same thing

事实上，这与

that cocaine does,

可卡因的作用完全相同，

just to a lesser degree. 短語搭配

只是程度要轻一些。

It's a drug after all. 表達脈絡

毕竟，它也是一种药物。

This dopamine stimulation

这种对多巴胺的刺激

is also the aspect of coffee

也正是咖啡

that makes it moderately addictive.

具有一定成瘾性的原因。

So, can you drink too much coffee?

那么，咖啡会不会喝太多呢？

It turns out there is a lethal dose of caffeine, 用詞

事实证明，咖啡因确实存在致死剂量，

which is somewhere around 150 mg

大约是每千克体重

of caffeine per kilogram of your body.

摄入150毫克咖啡因。

This means if you weigh 70 kg, 語法

也就是说，如果你体重70千克，

you would require 14,000 mg of caffeine

就需要摄入14,000毫克咖啡因

to overdose.

才会过量中毒。

Put into perspective, 表達脈絡

为了让你更有概念，

an average cup of coffee

平均一杯咖啡

contains roughly 150 mg of caffeine,

大约含有150毫克咖啡因，

meaning if you're 70 kg,

所以如果你体重70千克，

approximately 70 cups of coffee

大约70杯咖啡

would kill you.

就足以致命。

However, you would have to drink those cups

不过，你必须把这些咖啡

all at once,

一次性全喝下去，

making it effectively impossible 語法

所以在现实中，

to overdose on caffeine from coffee,

几乎不可能因喝咖啡而摄入过量咖啡因，

since you wouldn't be able to physically fit

因为你的胃根本装不下

that much in your stomach.

那么多咖啡。

You would also start experiencing

你还会开始出现

mania and hallucinations

躁狂和幻觉，

before getting to this point.

而且是在达到这个程度之前。

Caffeine also has a half-life 用詞

咖啡因的半衰期

of around 6 hours,

也大约是6小时，

so if you drank a standard coffee

所以，如果你喝了一杯普通咖啡，

with around 150 mg of caffeine,

其中含有约150毫克咖啡因，

after about 6 hours,

那么大约6小时后，

there'll only be 75 mg left in your system

你体内就只剩75毫克，

and you'll be feeling half of the effect.

你感受到的效果也会减半。

And 6 hours after that,

再过6小时，

you'll have 37.5 mg,

就只剩下37.5毫克，

leaving more room for adenosine 短語搭配

给腺苷腾出更多空间，

to jump back into action, 習語

让它重新发挥作用。

which is why you may reach for another cup 短語搭配

这就是为什么你可能会在

throughout the day

一天中再喝一杯咖啡，

to maintain that glorious alert

以保持那种美妙的清醒

and energetic feeling.

和精力充沛的感觉。

So, drink up and enjoy the buzz 用詞

所以，尽管喝吧，好好享受这股兴奋劲儿，

while it lasts. 短語搭配

趁它还没消退。

And for all of you in school,

至于所有还在上学的同学，

while we know caffeine is key, 語法

我们知道咖啡因很重要，

so are good deals on textbooks.

买到实惠的教材也同样重要。

So, we've teamed up with slugbooks.com 短語動詞

因此，我们与slugbooks.com合作，

to get you the cheapest prices

帮你以最低的价格

for the books you need.

买到需要的书。

All you have to do is head to 語法

你只需要前往

slugbooks.com/asapscience

slugbooks.com/asapscience，

and search the ISBN number

然后搜索ISBN编号，

of the books you're looking for.

也就是你要找的书的编号。

SlugBooks will then compare prices

随后，SlugBooks会比较

from all across the net.

全网各处的价格。

Seriously, we know how expensive 語法

说真的，我们知道

textbooks can be,

教材可能贵得吓人，

so hopefully this will save you some money.

希望这能帮你省些钱。

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