Why does our skin get wrinkly after taking a shower?



Why does our skin get wrinkly after taking a shower?

In: Biology

Two questions in your question: [Here’s a eli5 readable source.](https://kidshealth.org/en/kids/wrinkly-fingers.html)

1. Why does it happen?
2. What does it do for us as humans?
One: There is stuff on our skin that causes us to be water-resistant. If you wash your hands, this stuff causes the water to slide off. If you soak in water, however, the stuff that was making us water-resistant gets washed off. This allows the water to penetrate our skin, causing it to become waterlogged (filled with water).
Two: This is still up for debate, but my understanding as to why we evolved to get wrinkly when we get waterlogged is because it adds surface area, which makes friction increase. Essentially, we wrinkle because it makes it easier to keep our grip on things.

AFAIK the skin adapts to water by creating grooves so you have more grip Grabung things as the wetness generally lowers the grip. Similar things can be seen with for example Formula 1 race cars that switch to tires that look like of street cars compared to their normal tires that are without any grooves. Though the groves in car tires are so that the water on the street can go away from under the tires as without the water would build up between the road and the tire and it would „float“ on a thin layer of water instead of direct contact of the road.

Similar thing you can observe when you use plain and slick latex gloves compared to latex gloves with texture/groves while washing dishes. The textured ones usually help you hold the slippery plates much better as the rubber has at the tip of the groves some direct contact to the plate.

Someone can correct me but I think it has to do something with a phenomenon called osmosis. Skins are porous. But the inner layer has a high concentration of fluids within the cells. When they are long kept in water, it flows inside the cells to balance out the density of fluid across a porous membrane. This results in swelling of the skin.

Accorrding to my knowledge it’s a survival instinct. When our ancestors lived in wet invironments skin wrinkled to adapt to the moisture and provide friction.

Thanks for the answers everyone!