Stratum Corneum Cell Layers

Abstract

Although the stratum corneum (SC) exhibits disordered features when observed with conventional histologic sections, its cryostat section clearly shows the uniquely compact structure consisting of orderly overlapped layers of flattened corneocytes, supporting its important role in the skin barrier as well as in its water-binding capacity to keep the smooth and soft normal skin surface. Moreover, the SC is not uniform all over the body, showing big differences in its number of densely overlapped layers of corneocytes, reflecting the respective role unique for each body location. Thus, the SC of the thick palmoplantar skin shows nearly 50 cell layers of corneocytes in contrast to that of the genital skin or facial skin covered by thin SC consisting of less than 10 cell layers of flattened corneocytes. In such a way they exert their respective unique functional characteristics at each body location. By contrast, the hydration state of the SC seems to be influenced not only by the number of SC cell layers but also by other factors such as sweat and sebum secretion in addition to the turnover speed of the SC.