Human hair and skin layers. Coloured scanning electron micrograph (SEM) of a section through human skin with a hair (upper left) emerging from the surface. The skin layers, from top to bottom, are the stratum corneum (flaky, brown), composed of flattened, dead skin cells that form the surface of the skin. The dead cells from this layer are continuously being shed and replaced by cells from the living epidermal layer below (red, extending downwards around hair follicle). The lowest layer seen here is the dermis (grey-brown). This is a thick layer of fibrous connective tissue that supports and nourishes the epidermis. Magnification: x140 when printed 10cm wide.