The function and structure of the skin
The skinathe interface between humans and their environmentais the largest organ in the body. It weighs an average of 4 kg and covers an area of 2 m2. It acts as a barrier, protecting the body from harsh external conditions and preventing the loss of important body constituents, especially water. A death from destruction of skin, as in a burn, or in toxic epidermal necrolysis, and the misery of unpleasant acne, remind us of its many important functions, which range from the vital to the cosmetic (Table 2.1).
The skin has two layers. The outer is epithelial, the epidermis, which is firmly attached to, and supportedby connective tissue in the underlying dermis. Beneath the dermis is loose connective tissue, the subcutis/hypo-dermis which usually contains abundant fat (Fig. 2.1).