Why does the skin wrinkle in water when soaked?

Yey! It's summer time in the Philippines!! Swimming is one of the things we could do to refresh our body. . . .soaking our body to water makes our body freshen-up!, but did you notice that soaking your body leads your skin to wrinkle? and that after how many minutes it will return again to it's original form?

.....Here's a little study about Why this is happening.

The skin will wrinkle because or skin is made up of two layers.

TWO LAYERS OF THE SKIN
Outer Layer--EPIDERMIS
Lower Layer-- DERMIS

The outer layer (epidermis) produces an oily substance called sebum. You can see this substance when you touch a window or mirror and your "oily" fingerprint is left there. One job sebum does is it keeps water out of your skin-a job that it does very well. However, after long period of time in a swimming pool, shower, or bathtub, much of the sebum is washed off and your outer layer of skin starts to absorb water. As it absorbs water it swells, but since the epidermis is "tied" down to your dermis in certain spots, it expands more where it is not "tied" down and this causes your skin to wrinkle. 

The difference between your skin and a raisin is that raisins wrinkle because they shrink, but your skin wrinkles because it is getting bigger. Once you get out of the pool or tub, the water that your skin absorbed will evaporate, your skin will return to its usual size, and you body will produce more sebum. Your fingers and toes will be back to normal in no time.

..Patterns in wrinkled skin? How amazing huh?! Try reading this article to know more about this.

http://www.science20.com/genomicron/great_wrinkled_finger_debate-100816

Reference:
google.com
www.biology/cad.com