The seminal vesicles are 2 coiled sacculated tubes about 2 inches (5 cm) long which can be unraveled to 3 times of the length. They be located extraperitoneally on every side, in the base of the urinary bladder, lateral to the end point of the vas deferens and in front of the rectum. The lower narrow end of seminal vesicle (duct of seminal vesicle) joins the ductus deferens to create the ejaculatory duct.
The seminal vesicles, as their name indicates, don’t create a reservoir for sperms. Their secretions create a large amount of the seminal fluid. The secretion of seminal vesicles is somewhat alkaline, consisting of fructose, choline, and a coagulating enzyme named vesiculose.
The secretion of seminal vesicle includes fructose, that is not created anywhere else within the body. This gives a forensic evidence of the incidence of rape. Nevertheless, choline crystals supply the preferable foundation for determination of the presence of seminal fluid (Florence test).