The Naked Truth about your Skin
For those of you who enjoy the outdoors, you may marvel at the fabric technology that exists today. There are fabrics that keep you not too warm and not too cold; keep rain, snow, and ice out; protect you from the sun; and are “breathable.” There is nothing like a piece of clothing that you can take everywhere and be comfortable wearing. This is the story of our skin. From my perspective as a dermatologist, the skin is the most multi-talented part of the human body, yet often the most under-appreciated.
Like the clothing we wear, skin protects our body from the outside environment, but it also has so many more functions!
What does the skin do?
Prevents the entry of pathogens, or germs, into the body
Mounts the initial immune response if a microbe does penetrate through
Helps regulate body temperature
Keeps water and vital nutrients in our bodies
Makes vitamin D
Acts as a physical barrier to trauma
Sends the first warnings to our brains that danger is lurking
Skin Structure
Art by Maxwell Homer
So you might ask, “What’s the skinny on our skin?” Our skin is made up of three major layers:
The Epidermis
The first and outermost layer is called the epidermis. This layer mainly consists of keratinocyte cells, which turn over every four weeks, moving from the basal (bottom layer) to the top. Along the way, these cells change and discharge lipids, which form the seal around the keratinocytes to make our skin waterproof.
Another way to think of the epidermis is as a brick wall. The keratinocytes are the bricks and the lipids are the mortar. When you over clean your skin with harsh soaps, you are removing the mortar from this wall, thus making it easier for irritants, allergens, and even bacteria to penetrate the skin. People who have eczema are missing this mortar, which is why they are prone to inflammation and infections. People who have psoriasis make too many keratinocytes and therefore their skin flakes and sheds excessively.
Melanocytes, our pigment factories, make up less than 10% of the cells in our epidermis. However, they serve one of the most important functions of the skin. The melanocytes make melanin in little packages which are distributed to the keratinocytes. These little packages hover over the nucleus where our DNA is stored. The melanin helps absorb UV rays to protect your DNA. People who have vitiligo, a condition where the immune system destroys the melanocytes, have no protection against UV radiation. These areas of vitiligo are prone to sunburns and skin cancers and therefore require diligent sun protection.
As we age, uneven discoloration of our skin is the result of growing damage to our melanocytes over time. Every little bit counts! Wear your sunscreen every day over the exposed areas of your skin.
The Dermis
Now let’s get under your skin! Below the epidermis is the dermis. The dermis is made out of a collagen and elastin support structure which helps to hold hair follicles, oil glands, and sweat glands, as well as blood vessels and nerves. Sweat glands help us regulate temperature, whereas oil glands lubricate and waterproof our skin.
As we age and as a result of chronic UV exposure, our skin can produce less and less collagen and elastin. The breakdown products make our skin dull and yellow in appearance. The decreased amount of collagen and elastin creates fine wrinkles and reduces the flexibility of our skin. The easy tearing and bruising of the forearms of the elderly is the consequence of these changes.
Ask your board-certified dermatologist about routine skin products and procedures that can help you preserve and build collagen and elastin.
The Subcutis
The subcutis, the third layer of skin, serves to cushion, insulate, and connect the skin to our muscles and bones. Major blood vessels travel through this fatty layer to provide nutrients to our skin. Nerves help transmit signals from receptors for pain, pressure, and temperature to our brain. This important layer supports the upper layers of the skin to give us a full and youthful look!
The Naked Truth
Now you have the naked truth. When you see your board-certified dermatologists, the ultimate skin experts, have confidence that we listen and evaluate your concerns based on our in-depth knowledge of this complex system that makes up the largest organ of the body. You have skin in the game, so protect, appreciate, and love it!
