ELECTRON MICROSCOPIC STUDY OF HUMAN ADULT ECCRINE GLAND .I. DUCT

[摘要] Electron microscopic study of the adult eccrine sweat duct revealed within the epidermis one layer of inner cells and 2-3 layers of outer cells. The intradermal portion was composed of one layer of inner cells and one layer of outer cells. In the stratum corneum all layers of the intraepidermal duct had become keratinized and could not be distinguished from the surrounding keratinized epidermal cells. The inner cells of both the intraepidermal and the dermal portion of the eccrine duct possessed a perinuclear clear zone surrounded by a band of tonofilaments. The luminal portion of this band formed the periluminal filamentous zone. The function of this zone and shallow fissures present at the luminal junction of the inner cells of the intradermal duct, appeared to be the maintenance of luminal patency. Microvilli present along the luminal border possessed an extraneous fuzzy coating. The periluminal cytoplasm and the microvilli contained small vesicles similar to those found in the lumen. There was evidence that these vesicles passed from the inner cells into the lumen through disruptions of the plasma membrane and also as a result of pinching-off of microvilli.