Today's Tanners Demand More

Today's Tanners Demand More

As indoor tanning professionals, our customers have come to expect high levels of expertise regarding skin typing and tanning schedules, the importance of compliant eyewear and the ins and outs of state and federal regulations.

Our customers also count on us to guide them through the ever-changing selections of indoor tanning lotions. With today's expectations from demanding consumers, our role as skin anatomy and physiology experts is becoming a necessary trait as well. Therefore, we should take a few minutes and review the structure and function of the epidermis along with the origins of skin color.

Although the skin is less complex than most other organs, it is still an architectural wonder. It covers the entire body and accounts for about 7 percent of our total weight, making it the largest organ. It has been estimated that every square centimeter of the skin contains 70cm of blood vessels, 55cm of nerves, 100 sweat glands, 15 oil glands, 230 sensory receptors and about 500,000 cells that are constantly dying and being replaced.

The epidermis is the outer and visible layer of the skin. It contains four distinct types of cells-- keratinocytes, melanocytes, Merkel cells and Langerhans cells. Keratinocytes are by far the most abundant of these so we will discuss them first.

Keratinocytes

The primary role of keratinocytes is to produce keratin, a tough fibrous protein that gives the epidermis its protective properties. Tightly connected to one another, the keratinocytes arise in the deepest part of the epidermis from cells that undergo almost continuous reproduction. As these cells are pushed toward the skin surface by the production of new cells beneath them, they manufacture the keratin that eventually fills the cell.

By the time the keratinocytes reach the surface of the skin, they are dead, flat sacs completely filled with keratin. Millions of these dead cells rub off every day, giving us an entirely new epidermis every 35 to 45 days. In the normal, healthy epidermis, the production of new cells balances the loss at the surface. Where the skin experiences friction, both cell production and keratin formation are accelerated.

The Base of the Epidermis

The stratum basale, the deepest layer of the epidermis, is firmly attached to the dermis or second layer of the skin. This level consists of a single layer of cells representing the youngest keratinocytes. These cells divide rapidly. Occasional Merkel cells are seen among the keratinocytes. Each Merkel cell is directly associated with a disc-like sensory nerve ending and may serve as a receptor for touch.

Between 5 percent and 20 percent of the cells in the stratum basale are melanocytes. These make the dark skin pigment melanin. The spider-shaped melanocytes have many branches that reach and touch all the keartinocytes in the basal layer. Melanin is produced in the melanocyte and then transferred to the keratinocytes. Eventually, the keratinocytes contain more melanin than the melanocytes themselves. The melanin accumulates on the superficial side of each keratinocyte, forming a shield of pigment over the nucleus.

Scattered among the keratinocytes above the basale layer of the epidermis are Langerhans cells. These star-shaped cells are macrophages that help activate the immune system. Macrophages engulf and devour a wide variety of foreign materials, ranging from whole bacteria to foreign molecules to dirt particles. Macrophages also dispose of dead tissue cells.

Skin Color

Three pigments contribute to skin color--melanin, carotene and hemoglobin. Melanin, the most important pigment, is made from an amino acid called tyrosine. Melanin ranges in color from yellow to red to brown to black. Its production depends on an enzyme in melanocytes called tyrosinase. Freckles and pigmented moles are localized accumulations of melanin.

Carotene is a yellow to orange pigment resulting from certain plant products, such as carrots. It tends to accumulate in the outer layer of the epidermis and in the fat layers of the hypodermis our deepest layer of the skin. Its color is most obvious in the palms and soles, where the skin is thickest.

The pink tone of Caucasian skin reflects the crimson color of oxygenated hemoglobin in the capillaries of the dermis, or middle layer of skin. Since Caucasian skin contains the least amount of melanin, untanned Caucasian skin is nearly transparent and allows blood's color to show through. When hemoglobin is poorly oxygenated, both the blood and the skin of Caucasian people appear blue, a condition called cyanosis. Skin often becomes cyanotic during heart failure or severe respiratory disorders.

Having a better understanding of the skins structure and function will assist you in teaching your clients about the tanning process. With today's high expectations from American consumers it is essential that indoor tanning professionals stay current on all aspects of our service including anatomy and physiology.