The Pharmacology of the Skin

Abstract

The skin is divided into superficial epidermis, of ectodermal origin, and the deeper dermis, of mesodermal origin. The epidermis is stratified. Starting from within and going outwards, the layers are the basal, prickle cell, granular cell, and keratin or horny layer (the stratum corneum). The basic cell type is the keratinocyte, which moves and matures in an orderly way from the basal layer to the keratinised layer, which has the main barrier function. The transit time of the keratinocytes from basal to horny layer is about a month. The epidermis also contains melanocytes of neural crest origin which give skin its colour. The Langerhans’ cells of the epidermis may have some phagocytic function.