Ejaculatory duct
Ductus ejaculatorius
A paired, ≈2 cm duct formed by the union of the ductus deferens and the seminal vesicle duct that passes through the prostate to open into the prostatic urethra on the seminal colliculus.
Overview
Each ejaculatory duct begins near the base of the prostate, behind the neck of the bladder, where the ampulla of the ductus deferens joins the duct of the seminal vesicle. The two ducts converge as they run anteroinferiorly through the central zone of the prostate and open by slit-like orifices on the seminal colliculus (verumontanum) — a mound on the posterior wall of the prostatic urethra — one on each side of the opening of the prostatic utricle, a small blind pouch that is the male remnant of the Müllerian ducts (homologue of the uterus/vagina).
Their walls are thin, without the muscular coat of the ductus deferens; the expulsion of their contents depends on contraction of the prostate and seminal vesicles during emission.
- Location
Within the prostate, from its base (posterosuperior) to the seminal colliculus on the posterior wall of the prostatic urethra.
Anatomy
- Histology
Simple or pseudostratified columnar epithelium; thin fibrous wall without a distinct muscle coat.
- Development
Terminal part of the mesonephric (Wolffian) duct.
Function
- Convey sperm and seminal vesicle fluid into the prostatic urethra during emission.
Clinical significance
Ejaculatory duct obstruction
Congenital cysts (Müllerian/utricular), stones or post-infective scarring cause a low-volume, acidic, fructose-negative ejaculate with azoospermia or severe oligozoospermia and dilated seminal vesicles on transrectal ultrasound; treated by transurethral resection of the ejaculatory ducts.
Compiled from standard anatomy and physiology references — see the Reproductive System sources. For education only; not medical advice.