Why Do We Wrinkle When Wet?

Why do your fingers and toes get wrinkly when they’ve been in the water too long? Short answer: Your nerves. Longer answer: Evolution.

Hosted by: Michael Aranda
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[SpeedStrengthJames]

In the dry, you use slick tires, then in the wet you use tires with tread. Both equal getting more friction

Question, do they wrinkle in the same way every time? Like will your wrinkles always look the same? I've never tested it, maybe I will.

[hinayupak]

I explained osmosis to myself before i clicked this video.
did not even think about the function of the CNS in this.
thank you science for proving me wrong.
Great vid

[robinkarlberg]

That "Finger" in the thumbnail plus the title containing "Wet" made me think twice before clicking this video... I also checked if the URL spelled "youtube" instead of "redtube" -_-

[stellarfirefly]

I believe fingers/toes aren't wrinkly all the time for the same reason that tires with treads are actually not the best for friction when dry.  The wrinkles (and even fingerprints) help to channel fluids away, but when dry it is actually the amount of surface contact area that is the greatest determinant of friction.  It is also why untreaded tires (aka "slicks") are best for racing when on smooth, dry roads.

[futuresonex]

That makes sense. I have a spinal cord injury that has left me without normal feeling in my legs & feet, and, surprise, surprise, the skin on some of my toes doesn't wrinkle when wet while the skin on my other toes does. I never really paid much attention to it before, but it's cool to finally know why.

[bubbawatson]

I clicked on this so that I could tell my little brother how wrong he was. Now I get to tell him how he was correct... learning has never been so disappointing.

[cathexiad]

We covered this in uni, the other drawback from constantly wrinkled digits is that they are more prone to damage due to higher chance to catch on a sharp object and also more prone to breaks in the continuity of the skin due to weaker structure, opening up the deeper layers to infection.

[rogerwilco]

This totally blew me away. Never thought this would be so interesting. Thanks.

[bubbleman]

Let me save two minutes of your life.
To grip wet things better, now go enjoy those two minutes of life.

[alexz]

Well I didn't know this until today when hank found out and told me.

[ndviolin]

The effect is used as an objective way to detect nerve damage.

[stiimuli]

From what you described, it sounds as though the wrinkling is just a side effect. The body constricts the blood vessels possibly to help insulate the body in wet conditions and the wrinkling is just an inevitable result.

[meisgiorgos]

This was so much cooler than I was expecting haha!

[richardtaylor]

For those of you who wanted a bit more of the actual physiology, this is what I found: 

" Recent research shows that wrinkling is related to vasoconstriction.[13][14] Water probably initiates the wrinkling process by altering the balance of electrolytes in the skin as it diffuses into the hands and soles via their many sweat ducts. This could alter the stability of the membranes of the many neurons that synapse on the many blood vessels underneath skin, causing them to fire more rapidly. Increased neuronal firing causes blood vessels to constrict, decreasing the amount of fluid underneath the skin. This decrease in fluid would cause a decrease in tension, causing the skin to become wrinkly.[15]"

[davidszilvasi]

This has actually answered the question of my life... Thanks SciShow! :D

[redacted]

im never sure whether i should be disappointed or proud of myself when a scishow video teaches me nothing new

[johnchesterfield]

Is it just me? Because every time I wash my hands and touch paper I just gag. It just has a weird feeling and gives me the chills.

[LightningSeen]

I've always thought it was osmosis but I always had wrinkles whether in the beach or a private pool. Great video.

[horeja]

who else mistook the thumbnail for something else? **wink wink**

o_O