Wrinkly Fingers.

On one of our numerous walks my daughter asked, “why do we get wrinkly fingers in water?”

You would think something so commonplace would have a simple mechanism but no, my fine little friend, there is complexity is all things; including something so mundane as our skin.

Two essential theories exist: Our skin actually consists of many (6) layers, each connected to one another. The outermost layer of the epidermis — the one you can see — is the stratum corneum and contains dead cells called keratin. When immersed in water, the theory goes, the keratin cells expand like a sponge. To compensate for the increased surface area the layers of skin below are pulled into little mounds or gullies, i.e., wrinkles.

But our merry band of wild-eyed dermatologists are never satisfied and have proposed another theory, that of vasoconstriction. In this case when your body is immersed in water, our nervous system sends a message to your blood vessels to shrink causing blood to move away from the area. The loss of blood volume makes your vessels thinner, the skin folds in over them, and Walla! wrinkles.

Regardless the cause, what purpose could this wrinkling effect serve, the point of the original daughter question *points up*. Again some ideas have been proposed, the most common being that wrinkled fingers are better able to grip wet surfaces. Makes some sense, but the Fenton Theory postulates that it may be that wrinkles are merely a side effect of the complex structures that make up our skin. Those layers, my god.