Fine structure of the epithelium of the human ejaculatory duct.

Normal human ejaculatory ducts were examined by scanning and transmission electron microscopy. The lumen, which shows an irregular shape due to complex mucosal folds, is lined by a simple secretory epithelium. A strong cell polymorphism has been observed concerning cell height, nuclear shape, and amount of secretory organelles. Apart from small differences, the epithelium appears to be identical to that of the seminal vesicle and deferential ampulla. These observations demonstrate that the human ejaculatory duct is not only a passage for semen, but also contributes to its formation.