What Is Skin And How Does It Work? Pt 2
Okay, so we have an idea of what skin is. A bunch of layers upon layers.
And we have an idea of what it’s made of. Mostly proteins.
So how does it actually work?
How Does Skin Work?
Skin works a few jobs to keep us safe and put food on the table. Actually, it has about 6 jobs it does.
Protection
Secretion
Excretion
Heat Regulation
Absorption
Sensation
So let’s start at the top: protection. This one is pretty self-explanatory. I would say this is the biggest and most important job skin has. Without it, we’d fall ill all the time to the most basic of germs and external factors. But how does it work?
Simply put, those layers we talked about in my previous post contain more than just proteins. They contain other cells and hormones that activate when certain factors are present. When skin recognizes UV rays, it starts melanin production. When skin recognizes physical damage or trauma, it starts to repair itself. It also contains something called the “acid mantle” or “skin barrier”, as you might have heard. It’s a barrier within skin that protects us from bacterial invasions and trans-epidermal water loss or TEWL. This barrier is made up of protective lipids that are found between skin cells. I always explain it to my clients as a brick wall. The bricks are the skin cells and the mortar is the intercellular matrix (the barrier). Without the mortar, the skin cells just fumble and fall apart.
Now on to secretion and excretion. You might be wondering why I’ve joined them together to explain. While both of them are part of the same system, the endocrine system, they perform different specialty jobs.
Secretion is applied specifically to sebaceous glands (oil glands). These glands are usually attached to follicles* and produce sebum, an oily substance that protects the surface of the skin and lubricates both the skin and hair.
Excretion is applied specifically to sudoriferous glands (sweat glands). These glands excrete perspiration and detoxify the body by excreting excess water, salt, and unwanted chemicals through the pores*.
*Follicles refers to hair follicles. Pores refers to the openings on skin. Not all oil glands are attached to hair follicles, but the grand majority are.
Next is heat regulation. The body normally maintains thermoregulation through evaporation, perspiration, radiation, and insulation to keep an average internal temperature of 98.6°F (36.5-37.5°C). Sweat glands excrete sweat which evaporates on our skin’s surface, we radiate heat outwards when our body temperature exceeds our surrounding temperature, and our arrector and erector pili muscles contract to keep heat trapped within pores and follicles (this is what goosebumps are).
Moving on to absorption. While our skin is able to absorb certain chemicals like water and oxygen, it is not, in fact, a sponge. Some ingredients and chemicals can penetrate better than others, but overall don’t get as deep as you might think. This is not to say that your products are worthless (they aren’t) but to remind you that there’s only so much your skin can absorb.
Last, but not least, is sensation. Oh, to feel a fresh summer breeze on your face, or the warm sun on your arms on a cold fall morning, or a hug from your partner after you scraped your knee because you tried roller skates in search of that youthful feeling you used to get when you were a kid. Ahem.
Oh, right. Excuse me. Skin has sensory nerve endings in the dermis which respond to touch, cold, heat, and pressure. The nerve-end fibers detect stimuli, which sends a message to the brain to react. These sensory nerve endings are most abundant on the fingertips!
Okay, so those are the jobs skin has and does. It does them all in tandem to make sure you’re protected and able to thrive.
I will take this time to remind everyone that I am NOT a medical professional. The information I write about is information I was taught in school and have learned with experience. Technology and knowledge keep expanding every day. While I try to stay well-informed and up-to-date with anything and everything skin related, I’m only human and am bound to make mistakes. I implore you to keep me accountable. Ask questions, make comments, discuss with me whenever I say something that’s no longer the norm.
Anyways, thank you so much for reading! I appreciate any feedback to make this blog more enjoyable. Please feel free to leave a comment with any questions or concerns, and I’ll make sure to get back to you as soon as I can!
