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  • Whether you're swimming or washing the dishes, or just taking a nice long well-deserved bath,

  • if you're immersed in water for longer than 10 minutes, chances are your fingers and toes

  • will emerge looking like raisins. So what's up with the wrinkle digits?

  • For years, a scientist study the phenomenon was the result of some type of osmosis

  • caused by water passing into the dry outer layer of skin.

  • The influx of water, the thinking wet would expand the skin surface area but

  • not the tissue below its. The skin would bunch up and wrinkled. But in 1935

  • a pair of doctors noticed that this affects didn't happen

  • in their patients with nerve damage. One patient, for example, was a boy who had lost feeling in three of his fingers

  • The researchers found that when his hands got wet, the fingers that could feel

  • wrinkled as normal, but the ones that were numb, remain smooth.

  • It turned out that the pretty digits weren't caused by just a passive flow of water through the skin,

  • it was an active responsive of the nervous system to prolonged moisture.

  • The nervous system causes the wrinkling by constricting the blood vessel below the skin

  • which causes the upper layers of skin to pucker.

  • Since the phenomenon is caused by an involuntary nervous bound,

  • some biologists have thought that it must have some evolutionary function.

  • But what possible purpose could it serve? One recent theory

  • suggests that wrinkly skin may have given our ancestors a better grip on

  • working in wet conditions, like gathering food from a stream, or damp vegetation

  • May have also given us better footing while walking across the landscapes in the rain.

  • In a 2013 study,

  • evolutionary biologists tested this theory by asking subjects with either

  • wrinkly or non wrinkly fingers to pick up a variety of wet and dry objects like marbles.

  • They found that the subjects with wrinkly digits picked up the wet objects 12 percent faster

  • than their counterparts, but there was no difference when it came to picking up dry objects.

  • The wrinkles apparently helped channel the water away

  • much like the treads on your car's tires. So then this raises the question,

  • if wrinkly skin gives us a better grip, then why isn't our skin wrinkly all the time?

  • Well, maybe because shriveled fingers and toes are less sensitive,

  • which is no advantage at all. Thanks for asking, and if you'd like to submit questions

  • for us to answer, or get these quick questions a few days early

  • check out PATREON.COM/SCISHOW, don't forget to go to YOUTUBE.COM//SCISHOW and subscribe.

Whether you're swimming or washing the dishes, or just taking a nice long well-deserved bath,

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B2 US skin wet water wrinkle caused nervous

Why Do We Wrinkle When Wet?

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    Blair posted on 2015/05/31
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