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