1.Germinal matrix

This cluster of epithelial cells capping the dermal papilla can be divided into 4 indistinct zones that are arranged concentrically around the papilla. The zone closest to the papilla resembles the stratum basale of the epidermis in both structure and function. It contains both columnar epidermal cells and the melanocytes that give the hair its color. This germinal layer gives rise to the poorly keratinized cells of the medulla of the hair shaft and to the cells in the other 3 zones of the germinal matrix. Around the base of the bulb, this layer is continuous with the external root sheath that surrounds the entire bulb and shaft; near the surface, it is continuous with the stratum basale. Cells in the next layer form the cuticle. The most peripheral layer of the germinal matrix forms the poorly keratinized cells of the internal root sheath.