Why do our fingers and toes get wrinkly in water? Watch to find out! #STEMvee
[Video Description: Barbara, a white woman with curly red hair, is wearing a black jacket in front of a gray background.]
Transcript: Why do our fingers and toes wrinkle in water? We’ve all seen it: take a bath or a long shower, or go swimming, and you notice the tips of your fingers and toes wrinkle. We’re used to it, but do we know why this happens? The short answer is “no.” No one really understands exactly why our fingers and toes wrinkle, though there are some hypotheses. People used to believe that the fingertips draw water into the skin in a process known as osmosis, causing the skin to wrinkle. There are two evidences that reject the prevailing hypothesis: (1) Only the skin of the fingers and toes wrinkle—osmosis would cause all skin to wrinkle if that were the explanation; (2) If the nerves that control the hands had been damaged, fingers would not wrinkle after being soaked in water. The current working hypothesis involves digital vasoconstriction (narrowing of blood vessels in the fingers and toes). The blood vessels of the fingers constrict and the decreased volume in the deep layers of soft tissue essentially pull the skin in, creating the folds or wrinkles. Okay, but what’s the purpose of wrinkles? Research show that wrinkled fingers give a better grip in wet conditions. It could be working like treads on your car tires. The treads allow most of the tire to be in contact with the road and still have a way to expel water to give you a better grip and prevent slippage. Scientists believe wrinkled fingers could have helped our ancestors to gather food from wet vegetation or streams. The similar effect in the toes could help us to get a better footing in the rain. A big stumbling block is that no one knows whether any animal, aside from humans and primates, gets pruney fingers. So, we will need to study more about why humans have wrinkly fingers and toes! Vee!
