Human Skin - pH factor Biological functions, and types

by Nickolaos D. Skouras, PhD.

Epidermis
The epidermis is the outermost layer of the skin. It has two layers: the outer epidermis and the germinativum (jur•mi•na'•ti•vum). The outer epidermis protects the skin from weather, bacteria, and manages its own acidity and pH balance. Because it is comprised of dead, flattened cells, it can become dry and scaly. The germinativum is a slightly deeper level of the epidermis and is the site from which new skin cells ascend to the surface as dead cells 26 to 28 days later.

EPIDERMIS - barrier to the outside world, provides heat regulation, vast waste disposal system, replaces itself completely in 45-75 days.
STRATUM CORNEUM - outermost layer of the epidermis, made up of keratin proteins and lipids, thickness is less than a human hair, without the stratum corneum the epidermis would perish, can be fully replaced young 14 days and over 50 as long as 37 days.

Dermis
This dense, second layer gives skin its strength and elasticity. It contains blood and lymph vessels, hair follicles, muscles, nerves, and glands. It also contains a network of elastic fibers called connective tissue, which further strengthen, support, and elasticize the skin.

90% of the skin mass provides the skin's phyical strengh, regulates dermal blood flow, contains collagen and elastin, gives tone and texture.
COLLAGEN AND ELASTIN - both help to maintain water balance in the dermis, both add support for dermal components, nerves, and blood vessels, both act as a matrix for cell migration, metabolism, and growth.
COLLAGEN - derived from the Greek words "kolla" for glue and "gennen" for genesis, it is the glue of the connective tissue for skin support, gives skin its tone and texture by providing intracellular support, levels are effected by age and sun damage.
ELASTIN - is the fibrous protein that gives the skin resiliency and an elegant feel, provides the spring and snap to the young face, levels are effected by age, sun damage, and gravity.

Subcutaneous
The innermost layer of the skin contains fat cells which insulate the body and act as a reserve of calories and protect underlying tissue. This thickness varies with age, gender, and health.

The pH Factor
The acidity or alkalinity of a substance is measured on the pH scale, which ranges from 0 (extremely acidic, as in lemon juice) to 7 (neutral, as in water) to 14 (extremely alkaline, as in lye). Maintaining the skin's pH factor helps maintain a proper balance of the "acid mantle" which aids in protecting the body from bacteria and helps prevent moisture loss.

If destroyed by an alkaline substance, the acid mantle takes three or four hours to regenerate. Skin MatrixTM products work effectively to establish and maintain the proper pH level of the skin. An exception to this is any product containing significant levels of Beta Hydroxy Acids (BHAs). BHAs, by their nature, require an acidic pH around 3.0 in order to maintain an effective exfoliating ability. Skin MatrixTM products that contain BHAs are formulated so that, despite their low pH, they do not cause any negative effects on the acid mantle.