Some Observations on the Fine Structure of the Human Ductuli Efferentes Testis

The fine structure of human ductuli efferentes in fetal and adult epididymis was studied with the electron microscope.The epithelium of the ductuli efferentes is composed of columnal cells of both ciliated and non-ciliated types.The morphology of the ciliated cells do not differ significantly between fetal and adult cells. In the supranuclear zone, lysosomes and multivesicular bodies are recognized. In addition, adult cells show waste pigment granules and occasionally a lamellated granular endoplasmic reticulum.The fine structure of the non-ciliated cells suggests their function in absorption and secretion. Based on the morphological differences in their apical cell surface, the adult non-ciliated cells can be classified into 3 types. It was assumed that type I cells possess absorptive function and those of type II and III contribute to the secretion.Morphological differences by age in the adult cells are hardly recognizable except for senile degeneration.