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  • You breathe in about 17,000 times per day.

    每天你大約會呼吸17,000次

  • It's a process you rarely think about,

    這是一個你很少去想到的過程

  • 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

  • Your vital organs,

    你的重要器官

  • the gut,

    內臟

  • brain,

    大腦

  • bones,

    骨頭

  • lungs,

  • blood,

    血液

  • and heart

    和心臟

  • work together to sustain your life

    一起運作著以維持你的生命

  • by delivering oxygen to tissues throughout your body.

    藉由運送氧氣到身體的各個組織

  • Most of our cells need oxygen

    我們大部分的細胞都需要氧氣

  • 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.

    那只會有效的發生在短距離內

  • 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

  • it needs a transportation network.

    就需要一個運輸網路

  • 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.

    那也是讓血液呈現紅色的原因

  • To make these cells, the body uses raw materials

    為了生成這些細胞

  • 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

  • really begins in the gut.

    是從我們的內臟開始的

  • 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,

    食物被分解成更小的粒子

  • like iron, the building block of hemoglobin.

    像是血紅素的基本元素-鐵質

  • Iron is carried through the cardiovascular system

    鐵質是透過心血管系統運送

  • to the body's hematopoietic tissue.

    到身體的造血組織裡

  • This tissue is the birthplace of red blood cells,

    這個組織就是紅血球的來源地

  • 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

    腎臟透過釋放紅血球生成素

  • through the release of erythropoietin,

    來調節紅血球的多寡

  • 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,

    這數量等同於整個巴黎的人口

  • 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,

    但在氧氣到達肺之前,

  • the brain needs to get involved.

    大腦也需要介入

  • The brainstem initiates breathing

    腦幹會藉由神經系統

  • by sending a message through your nervous system,

    傳送開始呼吸的訊息

  • all the way to muscles of the diaphragm and ribs.

    並延續到橫膈膜和肋骨

  • This causes them to contract,

    這訊息讓他們開始收縮

  • thus increasing the space inside the rib cage,

    進而增加肋骨中央的空間

  • which allows the lungs to expand.

    讓肺擴張

  • That expansion drops your lungs internal air pressure,

    擴張會使肺內部的氣壓降低

  • making air rush in.

    讓空氣進入

  • 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.

    但它們比氣球複雜多了

  • Here's why.

    這裡就要告訴你原因

  • The red blood cells in the vessels within your lungs

    在肺臟血管理的紅血球

  • 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

  • If our lungs were shaped like balloons,

    如果我們的肺形狀就像氣球

  • 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

  • couldn't diffuse through.

    就無法擴散通過

  • 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

    它們的內部區隔成上百萬個

  • of miniature balloon-like projections called alveoli

    如小氣球般的凸出,稱做肺泡

  • that dramatically increase the contact area

    那顯然地增加了接觸的面積

  • to somewhere around 100 square meters.

    大約100平方公尺的面積

  • The alveolar walls are made of extremely thin flat cells

    肺泡壁則是由很多非常薄

  • that are surrounded by capillaries.

    由微血管包圍的細胞組成

  • 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

    接著這些帶氧的細胞會從肺

  • through the cardiovascular network,

    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.

    使每個細胞到達身體

  • 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.

    那些血管可以繞地球好幾圈呢

  • Propelling red blood cells through this extensive network

    將紅血球推進這些龐大的網絡中

  • requires a pretty powerful pump,

    需要非常有力的幫浦

  • and that's where your heart comes in.

    而這就是心臟的用途

  • 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

  • completing the body's team effort.

    維持身體協調的機能

  • 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

  • of tiny molecules of oxygen.

    微小的氧氣分子運輸網絡中

  • If just one part malfunctioned, so would we.

    只要有一部分發生故障,我們就活不了

  • Breathe in.

    吸氣

  • 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

  • Breathe out.

    吐氣

You breathe in about 17,000 times per day.

每天你大約會呼吸17,000次

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B1 中級 中文 美國腔 TED-Ed 紅血球 氧氣 細胞 身體 氣球

【TED-Ed】氧氣是怎麼在身體裡循環的? (How oxygen travels through your body - Enda Butler)

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    wangjiechin 發佈於 2017 年 08 月 11 日
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