Friday, June 17, 2011

The Science of Makeup: How the Skin Works Part 2

We left off last week discussing that what goes on, around and in our body affects our health.  We want to be healthy so we can feel good and look good.  That means taking care of our skin. Skins job is to serve as a protective barrier against bacteria, the environment, chemicals, poisons, and the wear and tear of life's everyday activities. Skin filters water in and out. Sweat glands in the skin control your temperature, sweating to cool off and reacting with chills and goosebumps when you are too cold. You have nerves in your skin that communicate subconsciously to you causing you to react with a flinch if someone catches you off guard. The top layer of skin (the first 15 - 40 layers) is called the epidermis. Most of this is made up of dead skin cells and it is a collection of flattened, protein filled cells stacked like layers on a cake. The cells move from layer to layer creating filament of protein called keratin and a grainy substance called keratohyaline. This protein and grainy substance kill the cells in a process called keratinization. And yes, Keratin is the same substance you find in your hair, as well as your nails, but the skin on your body is much smoother and flexible. At the end of this processes these cells become tough enough to do it's job as skin.



Skin Color
Melanocyte cells are responsible for the pigment or melanin in your skin. Everyone has the same number of these cells, regardless of their color. These cells produce tiny packages of granules called melanosomes, which is a super fast color delivery system that works nonstop all day, everyday. If we were to look at these cells close up, they are clear with a dark spot in the center with arms extended outward. The arms are what deliver the packages of color (melanosomes) to the keratinocyte cells. The keratinocyte cells carry the pigment of your skin and hair color.

Why do I have dark skin?
What you've learned so far is the system of skin works to create pigment and color.  The actual color of your skin is determined by a few different factors.  There are two major types of melanin produced by the melanocytes, eumelanin and pheomelanin.  People of color (Asian, olive, and dark skin) produce more emelanin than lighter skinned people.  People with fair or lighter skin produce more pheomelanin than people with darker skin. Whether or not you produce more emelanin or pheomelanin is determined through your DNA.

Other factors that contribute to your skins color are size and placement of the packages of color (melanosomes). The pattern of of melanosomes is different in people of color.  Melanosomes in darker skinned people are bigger and more spread out and more dense and packed together in people with fair skin. Also, the melanocytes in dark skin are very active and continuously working to produce more pigment than that of white or fair skin.  That amount is also determined by your DNA. The function of pigment is to protect against the sun's ultraviolet rays, so melanin is in all skin, dark and fair. 

People of color also have a unique protein structure that works below the dermis. The dermis has varying layers of thickness throughout your body. It has a network of blood vessel, hair follicles, nerve fibers, muscle cells, sweat glands, and oil glands called the sebaceous glands, bundles of protein fibers called collagen. Collagen is what gives the skin strength, and elastic fibers that allow it to stretch.  Wrinkles begin in this layer of skin when the collagen begans to wear out.  In Asian, olive and dark skin the structure of collagen explains why your skin reacts differently to stresses than white skin does. Dark skin is not thicker than fair skin; the thick bundles of collagen give dark skin a different physical tone. 

So why is all this important?
It's crazy to think that people have been, and still are, discriminated based on the color of their skin when we consider that skin color is a genetic and un-controlable functioning and makeup of our body determined by cells and DNA.  It's unfortunate and sad and we must continue to fight discrimination by empowering others with education.

Although I have provided a lot of info in the last two post on how skin works, there is still a ton about skin and why people of color are affected differently than fair skin, that doctors and researchers still don't know. It's important to find that information to treat and cure different conditions such as keloids (thick scars that grow larger than the original wound) which are more commonly found in skin of color. Using what we do know about the skin can help us to control, treat and care for it. We want nothing more than to wear our best skin!

Continue reading next Friday to learn about Acne in The Science of Makeup. The Science of Makeup will be a series of posts that will go in depth about the technical and theoretical aspects of beauty and skin care.

Beautiful Skin of Color: A Comprehensive Guide to Asian, Olive and Dark Skin. Cook-Bolden, Downie, Taylor. (2004).

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