ABSTRACT
Hair is a complex epidermal outgrowth, synthesized in the hair follicle. It is composed of 65 to 95% proteins, 1 to 9% lipids, 0.1 to 5% pigments (melanin), and small amounts of trace elements, polysaccharides, and water [1]. Human hair contains at least two cell types: the cuticle composed of overlapping scale cells and the cortex composed of spindle-shaped cortical cells. In the core of the cortex there may be condensed cells forming the medulla, which might be continuous or interspersed with air spaces [2]. The main features of the hair follicle are shown in Figure 1.1.
