Descriptions of the skin and its appendages tend to be a repetition of the basic facts well known by most clinicians. This article provides a more in-depth description of the epidermal cell layers, the dermis, and the appendages, as well as migrating cells, collagen, mast cells, macrophages, and lymphocytes. The appendages--hair, nails, sweat and sebaceous glands, and sensory receptors--are also described in depth.