Seminal Vesicle and Ejaculatory Duct Near the ampulla of each ductus deferens is a sac-shaped gland called the seminal vesicle(sem'i-nal ves'i-kl, relating to semen vesica, bladder). A short duct extends from the seminal vesicle to ampulla of the ductus deferens The duct from the semi nal vesicle and the ampulla of the ductus deferens join at the prostate gland to form the ejaculatory(e-jak u-la-tor- e, to shoot out) duct. Each ejaculatory duct extends into the prostate gland and ends by joining the urethra within the prostate gland(see figure 19.5a)