| Tanning
takes place in the skin's outermost layer, the epidermis. About five
percent of the cells in your epidermis are special cells called
melanocytes. When exposed to ultraviolet B light (the "burning"
rays), melanocytes "swell up" and secrete melanin - the pigment
which is ultimately responsible for your tan. The pinkish melanin
travels up through the germinative layer and is absorbed by other
skin cells. When exposed to ultraviolet A light (the "tanning"
rays), the melanin oxidizes (rusts) and becomes darker.. This
darkening is your skin's way of protecting itself against too much
UV light. This is called tanning, and the cells continue being
pushed upward, toward the "horny layer" of the epidermis. Heredity
dictates how much melanin your body's melanocytes naturally will
produce, since everyone has basically the same number of melanocytes.
For example, the skin of African Americans contains enough melanin
to create a black or brown skin color, while the skin of Caucasians
will secrete much less melanin and is pale.
Always avoid overexposure. Your tan should be acquired gradually,
according to the guidelines prescribed by your salon professional. A
sunburn occurs when too much ultraviolet light reaches the skin and
disrupts the tiny blood vessels near the skin's surface.
Why does a tan fade? Cells in the epidermis' germinative layer
(also called the living epidermis) are constantly reproducing and
pushing older cells upward toward the horny layer (dead epidermis),
where they are sloughed off in about one month. As your skin
replaces its cells, the cells laden with melanin fall off. In order
to stay tanned, you will need to continue exposure to UV light for
the new cells.
NEXT: The Truths
And Myths About Indoor Tanning |
