Many of us don’t give our skin much thought — except when it seems to betray us. Teenage acne, painful sunburns, scratchy winter dryness and mosquito bites alert us whenever our body’s largest organ is uncomfortable or misbehaving. But these superficial concerns tend to make us forget how the very top layer of our skin is an amazing example of Mother Nature’s brilliant design plan; it is our first defense against, well, everything. From protecting the body from germs and viruses to keeping us warm and cool and cushioning our interior organs, our skin is one of nature’s most brilliant packaging designs – read on for a closer look!
Photo © Curran Kelleher
Unlike crustaceans or insects, who wear their body armor on the outside, our skin is our first defense, keeping germs, viruses, bacteria, and other nasties out of our body. It holds our mushy interior mass together, and perhaps most critically, our skin keeps water levels inside our body at a very even keel — which is incredibly important, as even a 2% loss of water leads to dehydration (for anyone that’s ever experienced real dehydration — I have — it’s incredibly disorienting and sickening feeling since the brain needs plenty of water to keep working properly). Skin also keeps our body temperature stable; homeostasis inside the body is critical for efficient functioning of other organs, and it keeps us warm in cold temperatures, and works to cool us off in hot climes. And don’t forget plain old cushioning. Our outermost layer protect bones and offers a layer (thick or thin depending on how dense your skin is as well as how much underlying fat you have) between sensitive nerve endings and the outside world.
While all mammals have skin (and hair), we have a different type than reptiles, amphibians and birds. Amphibians have much thinner skins, which they can use can breathe through, and reptiles’ skin can be extremely thick since these cold-blooded animals need to retain heat as best they can. Bird skin is adapted to support feathers, and the skin of bird’s feet is especially fascinating; if you’ve ever seen ducks swimming a half-frozen pond or songbirds hopping along concrete in 1 degree weather, that’s because the skin on their feet is actually scales (specialized ‘skin’) and also because their feet can just be a lot colder than their bodies without damaging them.
Lead photo © Dan Zen
From the aforementioned examples, we can see that skin is extremely adaptable across species, and this is true within species too. In humans, there is a layer of skin that is only present in the palms of the hands and the soles of our feet, which is made of extra tough dermal material. Our skin also has sweat glands to cool us off and is host to over 1,000 different kinds of microorganisms.
But the most amazing part of our dermis and epidermis from a packaging perspective is probably its flexibility. If you’ve every hurt your ankle badly enough, you’ve probably noted some serious swelling. And of course, pregnant women take the cake; while it might not look exactly like it did beforehand, the skin on women’s stomachs is able to stretch to pretty amazing proportions, and then, depending on the age, elasticity of the woman’s skin, and degree of stretch, it can return almost entirely to its previous form. This is an amazing feat for any material, let alone one that performs all the other functions heretofore described. How amazing would it be to have this kind of material (that’s also biodegradable and low-energy to produce) to use for transporting and protecting contents from water loss and insect invasion?
Photo © Chris Costes
Speaking of insects, our skin doesn’t keep EVERYthing out, and in fact, there are some types of insects that can invade the skin after all. These are pretty much my worst nightmare; I’m not afraid of insects, spiders, amphibians, or rodents and generally consider them my friends. But burrowing creatures that get under your skin are fairly terrifying. The botfly of Africa is probably the most well-known. The adult fly lays the egg under your skin, where the larvae burrow into your body and can be impossible to remove. Supposedly, they can even get into your brain. So skin’s not perfect….but insects are a tough lot to beat!
While the term ‘hide’ is generally only used for large animal skins (horse, cow, etc.), as fans of the 1991 film Silence of the Lambs will know, human skin can also be tanned and used to make the same things that animals are made of, like handbags, shoes or wallets. While perhaps a bit of a ghoulish thought, it’s interesting to note that human skin is that tough of a material. Unlike previous entries in this category (banana leaves or Wombat rumps), I’m not going to take the next step and suggest other applications for human skin beyond which it is currently used, but simply marvel at the wonder of the stuff that surrounds me- and you – right now.
Starre Vartan is founder and editor-in-chief of Eco-Chick and author of The Eco-Chick Guide to Life (St. Martin’s Press). A green living expert, she contributes to The Huffington Post and Mother Nature Network (MNN.com)