Placeholder Image

字幕列表 影片播放

已審核 字幕已審核
  • A mosquito lands on your arm,

    一隻蚊子停在你的手臂上

  • injects its chemicals into your skin, and begins to feed.

    將化學物質注入你的皮膚,並開始以你的鮮血為食

  • You wouldn't even know it was there, if not for the red lump that appears,

    如果不是那伴隨著陣陣搔癢的紅色腫包

  • accompanied by a telltale itch.

    你甚至不會知道蚊子的存在

  • It's a nuisance, but that bump is an important signal

    雖然發癢的腫包很討厭,但這卻是你正受到

  • that you're protected by your immune system,

    免疫系統保護的重要訊號

  • your body's major safeguard against infection, illness, and disease.

    免疫系統是你的身體預防疾病或傳染病的主要保護措施

  • This system is a vast network of cells, tissues, and organs

    這個系統是一個由細胞、組織和器官組成的巨大網絡

  • that coordinate your body's defenses against any threats to your health.

    它們會互相協調身體的防禦機制,以預防對健康的任何威脅

  • Without it, you'd be exposed to billions of bacteria, viruses, and toxins

    若沒有免疫系統,你將會暴露在數十億細菌、病毒與毒素之中

  • that could make something as minor as a paper cut or a seasonal cold fatal.

    輕則造成如紙張劃傷般的影響,重則遭受致命症狀,如季節性感冒

  • The immune system relies on millions of defensive white blood cells,

    免疫系統依靠著血液中數百萬具防衛功能的白色細胞─

  • also known as leukocytes,

    也就是所謂的白血球來運作

  • that originate in our bone marrow.

    白血球源自我們的骨髓

  • These cells migrate into the bloodstream and the lymphatic system,

    它們會在血液和淋巴系統中移動

  • a network of vessels which helps clear bodily toxins and waste.

    淋巴系統是一個負責清除身體毒素和廢棄物的導管系統

  • Our bodies are teeming with leukocytes:

    我們的體內充滿了白血球:

  • there are between 4,000 and 11,000 in every microliter of blood.

    在每微升血液中,就有 4000 至 1,1000 顆白血球

  • As they move around, leukocytes work like security personnel,

    由於白血球們會到處移動,它們的工作就像保全一樣

  • constantly screening the blood, tissues, and organs for suspicious signs.

    持續搜查血液、組織和器官中有無可疑的徵兆

  • This system mainly relies on cues called antigens.

    免疫系統主要依賴一種名為「抗原」的線索來做判斷

  • These molecular traces on the surface of pathogens and other foreign substances

    這些分子會追蹤病源體的表面以及其他

  • betray the presence of invaders.

    會出賣侵略者存在的外來物質

  • As soon as the leukocytes detect them,

    一但白血球偵測到它們

  • it takes only minutes for the body's protective immune response to kick in.

    身體的免疫反應即會在數分鐘內見效

  • Threats to our bodies are hugely variable,

    由於身體受威脅的種類繁多

  • so the immune response has to be equally adaptable.

    所以免疫反應也要適應這些大量的威脅

  • That means relying on many different types of leukocytes

    也就是我們需要依靠不同類型的白血球

  • to tackle threats in different ways.

    以不同方法來處理這些威脅

  • Despite this diversity, we classify leukocytes in two main cellular groups,

    依照它們的多樣性,我們將白血球細胞分成主要的兩組

  • which coordinate a two-pronged attack.

    它們能互相協調出雙管齊下的攻擊

  • First, phagocytes trigger the immune response

    首先,噬菌細胞會將巨噬細胞和樹狀細胞

  • by sending macrophages and dendritic cells into the blood.

    送進血液中以觸發免疫反應

  • As these circulate, they destroy any foreign cells they encounter,

    這些細胞會在體內循環,並以吞噬的方式摧毀任何

  • simply by consuming them.

    它們遇見的外來細胞

  • That allows phagocytes to identify

    噬菌細胞隨後會辨別

  • the antigen on the invaders they just ingested

    他們剛吞下的侵略者身上的抗原

  • and transmit this information to the second major cell group

    並把抗原資訊傳遞給負責策劃防禦行動的

  • orchestrating the defense,

    第二組細胞─

  • the lymphocytes.

    淋巴細胞

  • A group of lymphocyte cells called T-cells go in search of infected body cells

    此時淋巴細胞中的 T 細胞們會找出受感染的體細胞

  • and swiftly kill them off.

    並立刻除掉它們

  • Meanwhile, B-cells and helper T-cells

    同時,淋巴細胞中的 B 細胞和輔助 T 細胞

  • use the information gathered from the unique antigens

    會依照剛剛的特殊抗原收集到的資訊

  • to start producing special proteins called antibodies.

    來產生特殊的蛋白質─也就是抗體

  • This is the pièce desistance:

    重頭戲來了:

  • Each antigen has a unique, matching antibody that can latch onto it

    每個抗原都有一個獨特,可以相互吻合的抗體

  • like a lock and key,

    它們就像鎖和鑰匙一樣

  • and destroy the invading cells.

    當兩者結合後,抗體就能消滅帶有此抗原的侵略細胞

  • B-cells can produce millions of these,

    B 細胞能夠製造數百萬的抗體

  • which then cycle through the body and attack the invaders

    它們會持續在體內循環並攻擊侵略者

  • until the worst of the threat is neutralized.

    直到最糟的威脅被解除

  • While all of this is going on, familiar symptoms,

    當上述過程發生時,常見的症狀

  • like high temperatures and swelling,

    如發燒和紅腫

  • are actually processes designed to aid the immune response.

    這些過程是為了幫助免疫反應的運作

  • A warmer body makes it harder for bacteria and viruses to reproduce and spread

    發熱的身體讓細菌和病毒難以在體內繁殖與散佈

  • because they're temperature-sensitive.

    因為它們對溫度很敏感

  • And when body cells are damaged,

    而當體細胞受損時

  • they release chemicals that make fluid leak into the surrounding tissues,

    它們也會釋放出讓胞內液流入周圍組織的化學物質

  • causing swelling.

    這會導致紅腫

  • That also attracts phagocytes,

    此化學物質也會吸引噬菌細胞

  • which consume the invaders and the damaged cells.

    它會一併吃掉侵略者和受損的體細胞

  • Usually, an immune response will eradicate a threat within a few days.

    通常,免疫系統會花數天來根除威脅

  • It won't always stop you from getting ill, but that's not its purpose.

    這期間可能會讓你生病,但這不是它的本意

  • Its actual job is to stop a threat

    它的本意是為了遏止體內的威脅

  • from escalating to dangerous levels inside your body.

    擴大到危險的階段

  • And through constant surveillance over time,

    隨著免疫系統持續監察

  • the immune system provides another benefit:

    它們也帶來了另一個益處—

  • it helps us develop long-term immunity.

    幫助我們發展長期免疫

  • When B- and T-cells identify antigens,

    一旦 B 細胞和 T 細胞辨識出侵略者的抗原

  • they can use that information to recognize invaders in the future.

    它們未來就能再次以此資訊辨識侵略者

  • So, when a threat revisits, the cells can swiftly deploy the right antibodies

    因此,當相同的威脅再次出現,它們可以即刻配對出與之符合的抗體

  • to tackle it before it affects any more cells.

    並對付它們,以防它們再影響更多正常細胞

  • That's how you can develop immunity to certain diseases, like chickenpox.

    這就是為何你能對特定疾病展現免疫的原因,例如水痘

  • It doesn't always work so well.

    但這個機制並非總是能正常運作

  • Some people have autoimmune diseases,

    因為有些人擁有「自體免疫性疾病」

  • which trick the immune system

    這個病症會讓

  • into attacking the body's own perfectly healthy cells.

    免疫系統攻擊自身的正常細胞

  • No one knows exactly what causes them,

    沒人知道導致這個病症的原因

  • but these disorders sabotage the immune system to varying degrees,

    但這類的系統失調除了造成免疫系統不同程度的破壞

  • and underlie problems like arthritis,

    也導致了一些疾病的發生,如關節炎

  • Type 1 diabetes,

    1 型糖尿病

  • and multiple sclerosis.

    以及多發性硬化症

  • For most individuals, however,

    對大多數人來說

  • a healthy immune system will successfully fight off an estimated 300 colds

    一個正常的免疫系統,在我們一生中能成功擊退約 300 次感冒

  • and innumerable other potential infections over the course of a lifetime.

    以及無數次的潛在傳染病

  • Without it, those threats would escalate into something far more dangerous.

    若沒有它們的保護,這些威脅可能擴大到更危險的地步

  • So the next time you catch a cold or scratch a mosquito bite,

    所以下次當你感冒或是搔抓著蚊子叮咬的腫包時

  • think of the immune system.

    記得想起我們的免疫系統

  • We owe it our lives.

    我們能好好生活都要感謝它

A mosquito lands on your arm,

一隻蚊子停在你的手臂上

字幕與單字
已審核 字幕已審核

影片操作 你可以在這邊進行「影片」的調整,以及「字幕」的顯示

B1 中級 中文 美國腔 TED-Ed 細胞 免疫 白血球 抗原 侵略

【TED-Ed】人類的免疫系統如何運作? (How does your immune system work? - Emma Bryce)

  • 4284 729
    IS LIU 發佈於 2018 年 04 月 22 日
影片單字