HOW SKIN FUNCTIONS
The skin is the largest organ of the body and is the only organ that actually replaces itself on a continual basis. The skin is self-cleansing, self-healing and self-regenerating.
• Keeps out bacteria, water, sun’s radiation, dirt and gases
• Synthesizes Vitamin D from sunlight for use by the body
• Holds in body temperature
• Eliminates harmful toxins
• Responds to stimuli, such as heat, cold, pain, pressure, touch
The skin is composed of three separate layers: the epidermis, the dermis and the subcutaneous layer. Each layer is distinct and different; however, they always function as one system. Whatever is done to one affects the other. The epidermis is the outermost layer of the skin. This remarkable shield consists of flat, dry, keratinized cells that flake constantly and are replaced by new cells formed in the layers beneath. The process takes approximately 28 days from the time cells are shed at the surface.
FOUR PRIMARY LAYERS IN THE EPIDERMIS
THE BASAL LAYER (Stratum Germinativum) is at the base of the epidermis. It is the cell birth layer and is composed of living cells. The new cells, formed through mitosis (cell division), begin to migrate upward to the surface of the skin, replacing the older cells that were shed.
THE SPINY LAYER (Stratum Spinosum) is next to the basal layer and consists of eight to ten rows of close-fitting cells filled with lipids, a group of organic compounds that are important to living cells.
THE GRANULAR LAYER (Stratum Granulosum) contains three to five layers of cells that gradually flatten out. As these cells mature, the lipids inside are spilled out into the intercellular spaces forming the Natural Moisturizing Factor (NMF). (See Natural Moisturizing Factor section.)
THE HORNY LAYER (Stratum Corneum) contains flattened, mature keratinized dead cells that have lost their metabolic function. They are continually being shed and replenished. Their function is to protect the layers beneath.
DERMIS AND SUBCUTANEOUS
The Dermis, directly beneath the epidermis, is the connective tissue that gives the skin physical strength. The dermis is also called the living skin. It is made up of fibrous connective tissue called collagen and elastin. There are also blood vessels, nerves, lymphatic vessels, sweat glands and sebaceous (oil) glands.
COLLAGEN is the tough, fibrous protein that helps skin hold its shape. Undamaged collagen fibers might be compared to thin rubber bands; they are very elastic and spring back easily when stretched. Ultraviolet light from the sun damages collagen, causing the fibers to hook together and become thick and lose their “spring.” This allows the skin to sag. Skin then falls into folds or wrinkles, the common sign of aging.
ELASTIN is the other protein found in the dermis. It also plays a role in the elasticity of the skin. There is considerably less elastin in the dermis than there is collagen. However, as the skin is damaged by ultraviolet exposure, the amount of elastin decreases.
THE SUBCUTANEOUS LAYER gives smoothness and contour to the body, contains fat for energy and acts as an insulator and a source of body heat. This layer of fatty tissue lies beneath the dermis and varies in thickness according to age, sex and general health.
NATURAL MOISTURIZING FACTOR
Chemicals in the stratum corneum bind and hold water molecules in and around the keratin cells. As the cells begin to harden and flatten, lipids are pushed into the spaces between the cells. Without this moisture, the cells would separate and cause severe cracks and peeling. These chemicals are called the Natural Moisturizing Factor (NMF). They are easily washed out of the skin by alkaline soap. When this happens, the moisture evaporates causing dryness and fine lines to appear.
WHAT IS A FREE RADICAL?
A “loose” molecule disrupts regular cell activity while trying to stabilize itself. The molecule becomes unstable and attaches to the cell wherever it can. This creates an imbalance in the cell, which affects the cell’s ability to nourish itself and eliminate waste properly. The result is a premature cellular collapse. Skin normally contains a small amount of free radicals and has its own defense against them. Stress, pollution and sunlight can cause free radicals to multiply and overwhelm natural defenses. Pharmagel® skin care products contain vitamins and other antioxidants to help control free radical formation. The products work to neutralize free radicals and render them harmless. They are the best defense against unnecessary aging.
FREE RADICALS AND AGING SKIN
The discovery of free radicals has led to a new understanding of the role that outside elements play in aging skin. Of all these elements, the sun causes the most damage.
ULTRAVIOLET LIGHT AND THE SUN
COLLAGEN DAMAGE - Ultraviolet light (UVA and UVB), natural or from sun lamps, penetrates the epidermis and attacks the collagen and elastin fibers in the dermis. The collagen converts to thick fibers that cannot be stretched, causing the skin to lose its elasticity.
ELASTIN DAMAGE - Ultraviolet light seems to be the culprit that stimulates and upsets molecular balance in the skin, causing elastin damage that results in premature aging.
OVEREXPOSURE - With overexposure to ultraviolet light, the epidermis thickens and produces a leathery look. The absence of exposure to the sun for a few weeks returns the epidermis to normal.
SKIN CANCER - There is a strong connection between skin cancer and sunlight. Some cancers are easy to cure, some can be fatal. Unprotected exposure to ultraviolet light should be avoided.