十万个为什么·科学阅读30篇（1）

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为什么手指泡水会起皱？

Wrinkling isn’t just passive swelling—it’s an active nervous system response controlled by blood vessel constriction.
Within five minutes of soaking, nerves signal blood vessels beneath the skin to narrow, pulling the outer layer downward.
This creates grooves that improve grip on wet or slippery objects, like wet fruit or river stones.
People with nerve damage in their hands don’t develop wrinkles, proving it’s not just water absorption.
Studies show wrinkled fingers drain water faster from surfaces, enhancing tactile sensitivity underwater.
The pattern resembles tire treads, channeling water away rather than trapping it between skin ridges.
This trait likely offered evolutionary advantage to early humans gathering food in streams or rainy forests.
Scientists now explore whether similar micro-texturing could improve waterproof gloves for surgeons or divers.