Hydration of the Skin Surface

摘要: The skin surface is tightly wrapped by an extremely thin but efficient biological barrier membrane, stratum corneum (SC). Since the SC interferes with permeation of even small molecules, such as those water, a barrier, it can protect underlying hydrated living tissue from desiccation in this dry atmosphere on Earth. It needless to say that also protects body invasion various external injurious agents. This function depends structural uniqueness SC, which consists closely overlapped corneocytes, flattened dead bodies fully differentiated epidermal keratinocytes, whose narrow intercellular spaces are packed unique lipids, components which, called hydroxyceramides, bind cornified envelope each corneocyte. Except for palmoplantar covered more than 50 layers corneocytes withstand strong physical force required support whole weight, other bodily regions mostly composed only 7–15 stacked [1]. surprising there exists just beneath and soft membranous structure SC. Then, why does elderly tend become rough winter?