Anatomy Of The Skin
The epidermis is the skin’s outer surface layer. It acts as the shield for the body and completely sheds itself approximately every 28 days. It is comprised of three to five distinct layers, depending on the type of skin. In the thick skin found on the palms of the hand and soles of the feet, for example, the epidermal layers from the inside out are the stratum basale, stratum spinosum, stratum granulosum, stratum lucidum and stratum corneum. In the thinner skin found over most of the body, usually only the strata basale, spinosum, and corneum are present.
Skin cell renewal takes place at the epidermis’ deepest layer: the stratum basale. This layer is closest to the dermis and reaps the most benefit from proper nutrients, oxygenation and debris removal. It is also the layer that that produces melanin, or skin pigment. If the body is functioning well on the inside, the stratum basale is able to get what it needs to renew cells. As we age, our body finds it more difficult to transport nourishment to this layer.
As you move through the layers of the epidermis, the skin’s function focuses less on cell renewal and respiration and more on defense. Cells flatten and thicken and receive little to no systemic nourishment. The fifth layer is the hardest, most protective layer of the skin, comprised of slightly acidic dead skin cells that inhibit growth of bacteria. The cells are glued together with moisturizing fats (ceramides, lipids and essential fatty acids) that help retain water in the skin. The pH balance of this layer is called the acid mantle.
The dermis and the epidermis share sebaceous and sweat glands, hair and pores, areas where the epidermis curves into the dermis. All these layers and their components work together to form the wonderful seamless organ of our skin. So learn to take care of it from the inside out, and from your soft underbelly to your toughest callus it will serve you long and well.