Why is our Skin Waterproof?

I am far from a biologist and I wouldn’t even call myself a science geek, but I was intrigued when I saw this article called Why our Skin is Waterproof because, well, I had never really thought about it before.

The common phrase, “Like water off a duck’s back” implies that these avian creatures are exemplary water resistant beings. Admittedly, it does have a better ring to it than, “Like water off of my hydrophobic lipids in my skins fat cells layer” – though I might start making an effort to use that to sound crazy smart!

But if you think about it, when we come in out of the rain, our clothing is wet, maybe your hair (I don’t have much hair to worry about) – but you aren’t soaked to the bone (though the dramatists among us may choose to argue that one). After stripping down from our waterlogged attire, a quick toweling off leaves you feeling great. You no longer consider yourself wet.

Lars Norlén at Sweden’s Karolinska Institute spent months researching skin samples shaved from volunteers. He would flash freeze the samples at a chilly -140° C to keep the cellular structure in place and then test its reaction to water.

This is the sciency-sounding explanation as published by New Scientist:

Lipids have a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. Normally, the two tails point in the same direction, giving the molecule a hairpin-like appearance. A group of lipid molecules typically arrange themselves into a two-layered sheet – or bilayer – with all of the tails pointing inwards. However, the lipid molecules in between the cells of the stratum corneum are splayed outwards so that the two tails of each molecule point in opposite directions.

These lipid molecules are stacked on top of one another in an alternating fashion. “By stretching out like this they form a more condensed structure which is much more impermeable than a normal bilayer,” says Norlén. This uniquely structured fatty layer prevents any water from getting past in either direction – except where the skin layer is modified to form pores.

Pores are the part of my body that cry when I exercise giving me a lovely glow of accomplishment.

We always take it for granted that our bodies just do what they do. Sometimes we wonder exactly what is left to learn about the way our bodies work that a scientist hasn’t already figured out. This new research doesn’t just answer the why, but also opens doors for further advancements in the tactile distribution of medications.

[Picture Source: Water Flowing On Woman Face – BigStockPhoto]