The skin is the biggest organ on the human body, and from keeping you cool to acting as one of your five senses, your skin does a lot more than just keeping your internal organs from plopping out.
We all think of our skin like the bag in a bag of peanuts: Bit more than a useful container that keeps all the good things together in one place. Our skin has a lot more to offer than being equal to the brown paper bag, though. Here’s everything it can do, as explained by dermatologist Lisa Chipps.
It’s A Triple Threat
The skin is comprised of three layers that interact. The outer layer, called the epidermis, is the bruiser of the trio, serving as a water-resistant barrier between our internal organs and the outside world. The dermis– which lies below the epidermis– is the brains, housing all the skin’s supportive structures. “The dermis is full of collagen, which provides the skin its structure, and it includes blood vessels, hair follicles, sweat glands, oil glands and nerve endings,” Chipps explains. Lastly, you have the much deeper subcutaneous tissue, the comedic relief of the trio, which just stores fat.
While the actual thickness of these layers remains fairly constant around the body, there are a few spots that need more or less padding. “The palms and soles are covered in thick epidermis tissue to secure from wear and tear, while the eyelids are made up of thinner tissue,” says Chipps. That’s due to the fact that the thinner skin allows the eyelids to better regulate how much light really enters our eyes.
As well as serving as a barrier to keep our insides in, the skin also helps to keep bad things out, as it’s geared up with a whole crowd of germ-busting cells. “The skin is full of immune cells called langerhans cells, which are always surveying the skin for germs,” Chipps explains. “When they find something that wants to enter the body and shouldn’t be, they stimulate the immune system to fight against it.” In other words, they’re the guys that yell, “Sound the alarm!!”
However, that’s not all they do: Langerhans cells also function as mediators between the immune system and any kind of “good” bacteria making a home of our epidermis– that is, other microorganisms that keep our skin healthy by fighting any foreign intruders– to ensure that no friendly fire decreases.
It’s An AC Unit (And A Heater)
Everyone knows the skin cools us down by sweating, which increases the amount of temperature we lose through evaporation. But there are other ways the skin keeps us at a pleasant temperature level. “When we’re hot, capillaries—which are tiny blood vessels in the skin—dilate, so blood circulates to the surface of our skin, where it’s cooled off by the outside air,” Chipps explains. “This now-cool blood then streams through the rest of the body, lowering our internal temperature.”.
These same blood vessels contract when we’re too cold, which prevents our warm blood from losing heat near the surface of the skin. Our skin also signals our body hair to stand up when we’re cold so that they trap heat, and to lay flat when we’re hot, which has the opposite effect.
Not those type of feelings, but rather the sense of touch. Thanks to our skin, touch is the first sense we develop as a fetus. The nerve systems depends on nerve cells (aka, touch receptors) embedded in the skin to pick up the outside world. “Some spot heat, some detect cold, some detect pressure, some detect itch, and some detect pain,” Chipps says. There are two main types of touch receptors: Thermoreceptors, which detect heat and cold, and Mechanoreceptors, which detect pressure.
While the thermoreceptor group is relatively self-explanatory, the Mechanoreceptor group includes 3 different sensory receptors. The Pacinian corpuscles lie throughout the body and detect deep pressure– a punch to the face, say. The Meissner’s corpuscles lie in our fingertips, lips, nipples and private parts, and they detect light pressure, like a soft smooch. Lastly, the Merkel’s discs lie in the ridges of our fingertips and detect texture, like sandpaper.
It Helps Prevent Cancer
Several types of cancer– including colon, breast and prostate cancer– have actually recently been related to vitamin D deficiency, which is something your skin can help with: The skin produces vitamin D when it’s exposed to sunlight. This doesn’t mean you should hang out at the beach all day without using sun block, naturally. You just need to expose your skin for around half the time it would normally take to start to burn to produce sufficient vitamin D for one day.
Remember: Your skin does you a whole lot of good as well as keeping your insides from being just a glob on the floor. The least you can do is rub it down with a little sunscreen every once in awhile.