The epithelial lining of the bovine ejaculatory duct.

The bovine ejaculatory duct is lined by a pseudostratified columnar epithelium. Two cell types are present: small basal cells and columnar principal cells in different functional states. The basal cells are able to accumulate lipid material. The principal cells are observed in a less active state and in a state of either increased endocytosis and fluid uptake or active spermiophagy. Endocytotically active cells are characterized by an apical brush border and a system of microvesicles, multivesicular bodies and lysosomal dense bodies. Cells involved in phagocytosis of spermatozoa are mostly provided with a smooth apical border, an expanded Golgi apparatus, many phagocytic vacuoles and condensing phagolysosomes.