I learned recently that our skin and brains are the most closely related organs. Apparently, both the brain and skin start off as the same types of cells and then differentiate. Also, our skin (our largest organ) and the brain communicate in ways that provide a feedback loop for sensory awareness, registration of emotions and much more.
Learning this had me fascinated and curious, and I decided to explore what skin looked like close up, so I searched on “electron microscope photography” and “human skin.” I was blown away by the photos. So much detail. So much going on. Look here!
I first thought of fish scales when I saw this image!
And look at the detail in this image above.
Another rather “scaly” looking close-up.
Well, people do talk sometimes of their skin feeling or looking scaly. It’s part of our lexicon when we speak of skin. Turns out we have about 35 billion skin cells, and as new cells emerge, they push out the older cells. We shed around 30,000 skin cells every minute, which results in the loss of roughly 43,200,000 each day. Word! 43 million shedded scaly skin cells a day. 43 million.
But then I found some information that really popped my brain and had me thinking. The epidermis, the outer layer of our skin (which includes the part of our skin we see every day) is comprised of more than just the skin’s surface. It consists of a number of levels, each with their own distinct role. As new cells are pushed upward through the other levels of the epidermis and toward the surface of our skin, they die along the way and eventually become filled with keratin, a very strong protein. “These dead, keratin-filled cells make up the outer parts of the epidermis and provide your body with the tough, protective overcoat it needs to survive. The dead cells on the outer parts of your skin are constantly shed and replaced by new ones. As a result, every 20-30 days, your body has an entirely new surface of skin.”
So I looked up keratin, and guess what? One type of keratin is found in the hair (including wool), horns, nails, claws and hooves of mammals. Another type of keratin is found in the nails, scales, claws, shells, feathers, beaks and quills of other animals.
In other words, the proteins in our outermost layer of skin are akin to the outer skin/hair/claws/scales of other animals. Now I can see when I first saw an electron microscope image of skin I thought of scales.
Fwiw, here are two close-up images of a human fingernail.
And here are two pics of human hair, the first damaged; the second, healthy.
Beware, though, if you start googling electron microscope photography images. It might be a while until you emerge. It was for me. 🙂