Hair from the bottom up can be divided into hair nipple, hair follicle, Mao Gen and hair dry four parts. The physiological characteristics and functions of hair are mainly determined by the scalp epidermis below the hair nipple, hair follicles and sebaceous glands.
The hair follicles are Mao Gen in the dermis layer, consisting of the Nemaugen sheath, outer Mao Gen sheath and wool balls, Nemaugen sheath in the later stage of the hair is the sheath layer adjacent to the hair directly. The Nemaugen sheath is a rigid, thick-walled keratin tube that determines the shape of the section when hair grows. The lower part of the Nemau sheath is three layers: the HUXLEY sheath, the HENLE sheath and the Nemaugen sheath surface. Before hair keratin, Nemaugen sheath and hair grow together, and its origins are the cells that reproduce at the bottom of the hair follicle. In close to the epidermis, the Nemaugen sheath is off with the epidermis and hair follicles.