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  • What do Charles Darwin, Michael Jordan, and Yoda have in common?

    查爾斯.達爾文、麥可.喬丹和尤達的共通點是什麼?

  • They, like many other historical and fictive individuals, are bald, in some cases by their own choice.

    他們跟許多歷史和虛構的人物一樣,都是禿頭,有些則是自己選擇要剃光頭髮。

  • For centuries, a shining dome has been a symbol of intelligence, but despite this, many balding people still wish their hair would return.

    好幾世紀以來,光亮的頭頂已成為聰明的象徵,儘管如此,許多禿頭的人們依然希望他們的頭髮可以長回來。

  • Scientists have long pondered, "Why do some people lose their hair, and how can we bring it back?"

    科學家仔細思考很久,「為什麼有些人會掉髮?我們該如何讓頭髮長回來?」

  • The full-headed among us have about 100,000 to 150,000 hairs on our scalps, and scientists have discovered two things about this dense thicket.

    正常人頭皮上的髮量介於 10 萬到 15 萬根之間,科學家已經發現這茂盛叢林的兩件事情。

  • Firstly, the sprouting hair we see is mostly made up of keratin, the protein leftover from dead cells that are forced upwards as new cells grow beneath them.

    第一,我們看到生長中的頭髮大部分都是角蛋白所產生,一種從死掉的細胞殘留下來的蛋白質,被底下新的細胞強迫向上推擠。

  • Secondly, the structures that drive hair growth are called hair follicles, a network of complex organs that forms before we're born, and grows hair in an everlasting cycle.

    第二,驅使頭髮生長的構造稱為毛囊,一個在我們出生之前就形成的複雜網絡器官,讓頭髮生長進入無止盡的循環。

  • This cycle has three main phases.

    這個循環有三個主要階段。

  • The first is anagen, the growth phase, which up to 90% of your hair follicles are experiencing right now, causing them to push up hair at a rate of one centimeter per month.

    第一個是生長期,90% 以上的毛囊正在經歷此階段,讓毛囊以每個月 1 公分的速度向上推擠頭髮。

  • Anagen can last for two to seven years, depending on your genes.

    生長期根據你的基因,可以長達 2 到 7 年。

  • After this productive period, signals within the skin instruct some follicles to enter a new phase known as catagen, or the regressing stage, causing hair follicles to shrink to a fraction of their original length.

    在這生產期之後,皮膚底下的信號下達指令讓部分毛囊開始進入新的階段,也就是退形期,或退化期,導致毛囊從原本的長度些微縮短。

  • Catagen lasts for about two to three weeks and cuts blood supply to the follicle, creating a club hair, meaning it's ready to be shed.

    退形期長達大約 2 到 3 星期,阻斷血液供給毛囊,形成杵状毛,也就是說可以準備脫落了。

  • Finally, hairs enter telogen, the resting phase, which lasts for ten to twelve weeks, and affects about 5-15% of your scalp follicles.

    最後,頭髮進入毛髮休止期,時間長達 10 到 12 週,大約影響 5 至 15% 的頭皮毛囊。

  • During telogen, up to 200 club hairs can be shed in a day, which is quite normal.

    在休止期期間,大約一天 200 根以上的杵状毛會掉落,這是正常現象。

  • Then, the growth cycle begins anew.

    之後生長週期再度開始。

  • But not all heads are hairy, and, in fact, some of them grow increasingly patchy over time in response to bodily changes.

    但並不是每個人都是頭頂茂盛,事實上,因為身體上的變化,有些頭髮隨著時間開始生長不均。

  • 95% of baldness in men can be attributed to male pattern baldness.

    95% 禿頭的男人都是雄性禿。

  • Baldness is inherited, and in people with this condition, follicles become incredibly sensitive to the effects of dihydrotestosterone, a hormonal product made from testosterone.

    禿頭可以遺傳,有如此情況的人,毛囊對二氫睪固酮非常敏感,這是一種從睪丸產生的賀爾蒙。

  • DHT causes shrinkage in these overly sensitive follicles, making hair shorter and wispier.

    二氫睪固酮導致敏感的毛囊萎縮,讓頭髮又短又纖細。

  • But loss isn't sudden.

    但掉髮並不是突然發生。

  • It happens gradually, along a metric known as the Norwood Scale, which describes the severity of hair loss.

    而是慢慢地,有一個說明各種掉髮階段的分級法,也就是諾伍德規模。

  • First, hair recedes along the temples, then hair on the crown begins to thin in a circular pattern.

    首先,頭髮延著太陽穴逐漸減少,之後頭頂上的頭髮開始稀疏,形成圓形狀。

  • At the highest rating on the scale, these balding areas meet and expand dramatically, eventually leaving only a ring of sparse hair around the temples and the back of the head.

    達到最高級的規模時,這些禿頭的區塊戲劇性的接合擴展,最後只留下太陽穴以及後腦勺附近稀疏的頭髮。

  • Genetics isn't all that drives hair loss.

    基因並不是掉髮的主因。

  • Long periods of stress can release signals that shock follicles and force them into the resting phase prematurely.

    長期在壓力之下也會釋放信號衝擊毛囊,迫使他們提早進入休止期。

  • Some women experience this after childbirth.

    有些女人在生產後經歷掉髮階段。

  • Follicles might also lose the ability to go into anagen, the growth phase.

    毛囊也可能喪失能力進入生長期。

  • People going through chemotherapy treatment temporarily experience this.

    接受化療的人們也會短暫經歷此階段。

  • But while balding may look permanent, scientific investigation has revealed the opposite.

    即使禿頭看似永久,科學研究發現不一樣的結果。

  • Below the skin's surface, the roots that give rise to our hair actually remain alive.

    在表皮底下,給予我們頭髮生長的根部依然活躍著。

  • Using this knowledge, scientists have developed drugs that shorten the resting phase, and force follicles into anagen.

    透過運用這理論,科學家已經發明藥物可以簡短休止期的時間,強迫毛囊進入生長期。

  • Other drugs combat male pattern baldness by blocking the conversion of testosterone to DHT so that it doesn't affect those sensitive follicles.

    其他藥物透過阻止睪丸激素轉換成二氫睪固酮來對付雄性禿,好讓他們不會影響敏感的毛囊。

  • Stem cells also play a role in regulating the growth cycle, and so scientists are investigating whether they can manipulate the activity of these cells to encourage follicles to start producing hair again.

    幹細胞也是控制生長週期的主要角色,所以科學家正在研究是否可以控制這些細胞的活動,來刺激毛囊開始再次生長頭髮。

  • And in the meantime, while scientists hone their hair-reviving methods, anyone going bald, or considering baldness, can remember that they're in great company.

    與此同時,當科學家不斷尋找讓頭髮再生的方法,任何禿頭的人或擔心禿頭的人,記得你不是孤單一個人。

What do Charles Darwin, Michael Jordan, and Yoda have in common?

查爾斯.達爾文、麥可.喬丹和尤達的共通點是什麼?

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B2 中高級 中文 美國腔 TED-Ed 毛囊 禿頭 頭髮 生長 階段

【TED-Ed】為什麼會禿頭?(Why do some people go bald? - Sarthak Sinha)

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    SylviaQQ 發佈於 2016 年 04 月 22 日
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