Postnatal Differentiation and Regional Histological Variations in the Ductus Epididymidis of Rams*

The caput, corpus and cauda regions of the ductus epididymidis consisted of six histological segments that showed regional variations. The postnatal differentiation of the different segments started from birth and progressed till maturity. The simple epithelium at birth gained progressive pseudostratification. Similarly, the appearance of stereocilia, different types of cells in the epithelium and the smooth muscle layers around the epididymal tubules progressed and at different periods of postnatal development, the typical adult characteristics were achieved. The diameter of the epididymal tubules also increased, as age advanced. The developmental progression was disto-proximal i.e., the postnatal differentiation started in the terminal segment and then ascended through the middle and initial segments. The progression in the increase in height of the epithelium was varied in the three regions, whereas the progression in the increase in the diameter of epididymal tubules was uniform.