所有能够自我更新的组织都存在干细胞,这些细胞长期生存,有强大的增殖分化潜能,有助于细胞更替。鼓膜的外表层属于角质细胞,表层角质细胞持续不断更新、脱落,然后又由基底层的细胞持续不断地增殖分裂更替。为了让表皮维持固定的厚度和功能,细胞产生和丢失的速度必须一致。因此, All self-renewing organizations have stem cells that survive long-term and have strong proliferative and differentiation potential, helping to replace cells. The outer surface of the tympanic membrane belongs to keratinocytes, the surface of keratinocytes continuously updated, shedding, and then from the basal layer of cells continue to proliferate and divide and replace. In order for the epidermis to maintain a constant thickness and function, cells must be produced and lost at the same rate. therefore,