Observation of the histological structure of Bos grunniens oviduct during pregnancy

Histological and histochemical(periodic acid Schiff,PAS) methods were used to examine the histological structure of yak oviduct during pregnancy.The results showed that the wall of yak oviduct was composed of mucous membrane,tunica muscularis and tunica adventitia.The mucous epithelium consisted of ciliated cells,secretory cells,a few of basal cells and peg cells.The apices of secretory cells displayed cytoplasmic protrusion in both the infundibular and ampullary regions of yak oviduct during pregnancy.There were two types of protrusions in the infundibulum.The first type had many positive granules in PAS reaction in the supranuclear cytoplasm without nuclei.The other one contained nuclei without positive granules in PAS reaction.In the ampulla,the protrusions of secretory cells all belonged to the former but the secretory cells had no protrusions in the isthmus .The lamina propria was loose connective tissue with serous glands in the isthmus.The mucosa membrane was thrown into longitudinal primary folds which were high,narrow and had many branches in the infundibulum and ampulla,but in the isthmus the folds were low,broad and had few branches.The tunica muscularis were composed mainly of smooth muscles which were the thickest in the isthmus.The tunica adventitia was serous membrane,but in the mesosalpinx,it was connective tissue.