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  • Scientific American Instant Egghead

  • Ow! A paper cut!

  • Paper cuts are usually small and shallow injuries.

  • So why do they hurt so much?

  • A close look at the anatomy of our skin and the structure of paper reveals a few explanations.

  • We usually get paper cuts on our hands and fingers, where our skin is packed with neurons.

  • Some of these neurons, called nociceptors, detect potential harm.

  • These cells respond to high temperatures,

  • harsh chemicals

  • and any pressure that threatens to break the skin.

  • Nociceptors trigger a cascade of electrical and chemical signals

  • that eventually reach the brain, informing it about injury.

  • In turn, our brain makes us aware of injury with the experience of pain.

  • Also, a paper cut is not quite as clean as it looks.

  • A paper's edge may seem perfectly smooth,

  • but on a microscopic level, it's actually pretty jagged.

  • A thin piece of paper cuts through skin more like a saw than a knife,

  • ripping apart our cells.

  • And paper leaves behind chemical-coated particles, irritating the wound.

  • Another thing, since paper cuts are generally shallow,

  • they don't bleed or clot very much.

  • That means damaged tissues and neurons remain exposed.

  • Every time we use our hands, the wound flexes open, disturbing these neurons.

  • Finally, we should also consider the psychology of a paper cut.

  • We probably pay more attention to a paper cut because it's on a body part we use so often.

  • It's also surprising and kind of upsetting to be injured by something as seemingly benign as paper.

  • For Scientific American's Instant Egghead, I'm Ferris Jabr.

Scientific American Instant Egghead

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為什麼剪紙這麼疼?- 即時蛋頭#25 (Why Do Paper Cuts Hurt So Much? - Instant Egghead #25)

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    大菲鴨阿 發佈於 2021 年 01 月 14 日
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