Name: 【TED-Ed】氧氣是怎麼在身體裡循環的？ (How oxygen travels through your body - Enda Butler)
Uploaded: 2017-08-11T21:59:57.000Z
Duration: 5 min 10 s

You breathe in about 17,000 times per day.

程度副詞

but behind the scenes, a huge coordinated effort is playing out.

但在這背後正有著巨大的協調力量運作著

by delivering oxygen to tissues throughout your body.

藉由運送氧氣到身體的各個組織

because it's one of the key ingredients of aerobic respiration.

因為這是呼吸作用其中一個重要的原料

That's the process that produces a molecule called ATP,

這個過程製造一種分子稱做ATP（三磷酸腺苷）

which our cells use to power their many incredible functions.

使我們的細胞有更好的作用和功能

But getting oxygen throughout our bodies is a surprisingly difficult task.

但將氧氣輸送到全身卻是意外困難的任務

Gas enters cells by diffusing in from their surroundings.

氣體藉由擴散作用從原本的環境進到細胞裡

And that only happens efficiently over tiny distances.

So for oxygen to reach the cells within our bodies,

所以為了讓氧氣能抵達我們身體的細胞

This is where our 20 trillion  red blood cells come in.

那就是我們身體裡20兆個紅血球的用途

Each one contains about 270 million oxygen-binding molecules of hemoglobin,

每個紅血球都包含著27億個血紅素的氧結合分子

which is what gives blood its scarlet hue.

To make these cells, the body uses raw materials

that become available from the food we eat.

身體以我們攝取的食物中作為原料

So in some ways, you could say that oxygen's journey through the body

在某方面，你可以說身體中氧氣的旅程

Here, in an amazing display of mechanical and chemical digestion,

這是一個令人驚奇的機械性及化學性消化作用

food gets broken down into its smallest elements,

like iron, the building block of hemoglobin.

Iron is carried through  the cardiovascular system

This tissue is the birthplace  of red blood cells,

and it can be found enclosed within our bone marrow cavities.

而這也可以在我們的骨髓的空隙中找到

The kidneys regulate  our levels of red blood cells

a hormone which causes marrow to increase production.

紅血球生成素是刺激骨髓增加紅血球產量的荷爾蒙

Our bodies churn out roughly 2.5 million red blood cells per second,

我們的身體每秒大概會製造出２５０萬的紅血球

a number equivalent to the entire population of Paris,

so that oxygen that makes it to the lungs will have ample transportation.

所以運送到肺的氧氣會有充足的運送

But before oxygen  can even reach the lungs,

by sending a message through your nervous system,

all the way to muscles  of the diaphragm and ribs.

thus increasing the space inside the rib cage,

That expansion drops your lungs internal air pressure,

It's tempting to think of our lungs as two big balloons,

這讓人聯想到我們的肺就像兩顆氣球

but they're actually a lot more  complicated than that.

The red blood cells in the vessels within your lungs

can only pick up oxygen molecules that are very close to them.

只能接收離他們非常近的氧分子

air that was not in direct contact with the balloon's inner surface

那些沒有跟氣球面直接接觸到的氧分子

Luckily, our lungs' architecture ensures that very little oxygen is wasted.

幸好，我們肺的結構可以確保只有一些些氧氣會被浪費掉

Their interior is divided into hundreds of millions

of miniature balloon-like projections called alveoli

that dramatically increase  the contact area

The alveolar walls are made of extremely thin flat cells

Together, the alveolar wall and capillaries make a two-cell thick membrane

肺泡壁和微血管一起形成了兩個細胞壁厚的薄膜

that brings blood and oxygen close enough for diffusion.

足以讓血液及氧氣發生擴散作用

These oxygen-enriched cells are then carried from the lungs

通到匯集龐大血管的心血管的網絡中

a massive collection of blood vessels that reaches every cell in the body.

If we laid this system out end to end in a straight line,

如果我們將這些系統從頭排到尾拉成一直線

the vessels would wrap around the Earth several times.

Propelling red blood cells through this extensive network

將紅血球推進這些龐大的網絡中

The human heart pumps an average of about 100,000 times per day,

人類的心臟每天平均會跳１０萬次

and it's the powerhouse that ultimately gets oxygen where it needs to go,

這個動力室讓氧氣被輸送到需要的地方

Just think - this entire complex system is built around the delivery

想一想，這整個複雜的系統建構在一個

If just one part malfunctioned, so would we.

只要有一部分發生故障，我們就活不了

Your gut, brain, bones,  lungs, blood, and heart

你的內臟、大腦、骨頭、肺、血液和心臟

are continuing their incredible act of coordination that keeps you alive.

正持續著它們難以置信的協調合作，來維持你的生命