18 Jun Skin Anatomy
The skin is the largest organ of the human body, 16.1 – 21.5 sq ft. or 1.5 – 2.0 sq. meters for the average adult, or approximately 16% of total body weight. It is not an inert covering however, it has several functions. The skin protects, senses (heat, cold, vibration, touch, pressure and injury), regulates heat loss and retention; stores fat in the hypodermis, regulates vitamin D synthesis; and communicates nonverbally and aesthetically.
In order to provide this wide variety of functions the skin is composed of several layers. The epidermis or outer most layer is composed of five different layers itself. The epidermis also contains the melanocytes which produce melanin. Melanin is a normal and protective skin component which can accumulate abnormally, as in age spots, melasma or just uneven pigmentation. These abnormalities can be managed with pharmaceutical-grade topical creams and light based therapies. Just under the epidermis is the dermis.
The dermis not only contains the blood vessels, nerves and the bases of sweat glands and hair follicles but also holds the collagen and elastin matrix. This matrix, which provides the structure and support for the overlying epidermis, becomes less organized and thinner as we age leading to wrinkling and sagging. The matrix can be coaxed to reinvigorate itself using a variety of collagen induction therapies like microneedling.
Finally, the subcutaneous layer, or hypodermis, sits below the skin and contains up to 50% of the body fat. This layer also contains its own connective tissues which anchor the skin to underlying bones and muscles. These connective tissues are responsible for the dimpling known as cellulite. The appearance of cellulite can be improved with body contouring and circumferential reduction using radio frequency devices like the Venus Freeze.