posterior ejaculatory duct Duct that connects the ejaculatory bulb to the aedeagus in the male adult genitalia. It is 300 micrometers long with a diameter of 11-18 micrometers, continuous with the intima lining the ejaculatory bulb. Its wall is chitinous and 0.5 micrometers thick, with small scattered nuclei on its surface. The duct passes below the rectum and opens below the ninth and tenth abdominal segments. FBbt:00004966 fly_anatomy.ontology male-specific anatomical entity ejaculatory duct epithelium duct