Why do our fingers and toes get wrinkly and pruney in the bath, or in water? This video explores some of the concepts surrounding this phenomenon.
For our skin to begin wrinkling, the skin reduces the size of nearby blood vessels. the layered structure of the skin and the extra space available due to the smaller blood vessels, an influx of water moves into the area. The top layers are able to swell, while the lower layers stay intact and the skin bulges out into a wrinkly appearance. There are some interesting insights into how this works, and some of the hypotheses behind WHY this occurs.