人头发为前额、两耳和后颈以上生长的毛发,在皮肤表面以上部分称为毛干,在毛囊内部分称为毛根,毛根下段膨大部分称为毛球,突入毛球底部的部分称为毛乳头。毛乳头含有丰富的毛细血管和神经,以维持头发的营养和生长。 Human hair for the forehead, ears and hair growth above the neck, the above part of the skin surface is called the hair shaft, hair follicles within the part called the hair root, the lower part of the hair root swelling called hair ball, protruding into the bottom part of the hair ball is called Dermal Dermal papilla contains abundant capillaries and nerves to maintain the nutrition and growth of the hair.