Why Do You Fingers Go Wrinkly After A Long Bath?

Many people think that the water has some how dried up their skin but, in fact, the opposite is true. The answer is to do with osmosis, which is the movement of water from a region of its higher concentration to a region of its lower concentration across a semi-permeable membrane.

In the case of your fingers, the semi-permeable membrane is the cell membrane of your skin cells. When you get into a bath or ordinary water, the water contains very little salt. The inside of your finger cells does contain salt ~ it is more concentrated in terms of salt.

It follows then, that the cytoplasm of skin cells is less concentrated in terms of water. Water therefore passes by osmosis through the membrane of the skin cells and into the cells themselves. This causes the cells to swell up and causes extra folds in the finger skin. The wrinkles are caused by soggy skin, rather than skin drying out.

I think this is wrong.

It is all due to the process called osmosis. Osmosis is a process in which a passage of water from a dilute solution to a more concentrated solution across a partially permeable membrane, so moisture had move out of the skin, causing the fingers to wrinkle.