Composition of the Skin
The skin has two main divisions:
1. Epidermis, which is the outermost layer of the skin (also referred to as cuticle or scarf skin)
2. Dermis, which is the underlying, or inner, layer of the skin (also called derma, corium,
cutis or true skin)
Under the dermis layer is the sub-dermis or subcutaneous division, composed of fatty tissue.
Epidermis
The epidermis makes up the outer layers of the skin. It's almost like a bag that covers you and pro-
tects you from the environment. The epidermis is composed of five layers of cells with differ-
ing characteristics and contains no blood vessels.
Stratum Germinativum
At the lowest level of the epidermis you will find the stratum germinativum. It begins with the stra-
tum basale, or basal cell layer, which is a single layer thick. It is here where skin cell growth
occurs through mitosis or cell division. Basal cells are constantly dividing and pro-
ducing new cells that are pushed toward the surface of the skin to replace cells that
have been shed. Keratinization, the chemical conversion of living cells into dead pro-
tein cells, begins when the newly produced cells are pushed toward the surface. As the
newly produced cells move toward the surface and farther away from the stratum ger-
minativum, they flatten out, lose most of their water, die and, as keratinized cells, are
finally shed. This process takes from 25 to 28 days, depending mostly on the area of
the body, age and/or health of the individual. Melanocytes are also found in the
stratum germinativum. These cells produce the melanosomes or pigment granules containing
melanin that give color to the skin. The amount of melanin present will determine the skin's
color. Brown skin contains a large amount of melanin while skin with little melanin will appear pale
or pinkish. Melanin protects the skin, particularly in layers closest to the surface, by screening out
harmful ultraviolet rays.
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SALON FUNDAMENTALS
Stratum Corneum (
KOHR-nee-um)
Stratum Lucidum (
LOO-si-dum)
Stratum Granulosum (gran-yoo-
LOH-sum)
Stratum Spinosum (spye-
NO-sum)
Stratum Germinativum (jur-mih-nah-
TIV-um)
or Stratum Basale (Basal Layer)
"The word stratum
means layer."
