Ducts

Ducts of the Prostate

Ashley Davidoff MD

The Common Vein Copyright 2011

Introduction

The lower genitourinary system has dual responsibility for the transport of urine and semen.  Urine is the product of the kidneys and semen is the product of the testes, seminal vesicles, prostate and bulbourethral glands (aka Cowper’s glands).

 The sperm and fluid from the seminal vesicle are transported via the paired ejaculatory ducts into the verumontanum, which is a mound of tissue in the middle of the prostatic urethra.  The prostatic fluid is brought to the urethra by 15-20 ducts.

Ducts of the Urogenital System of the Pelvis

The diagram reflects the ductal systems involved in the urogenital tract including the ureteral orifices that empty into the bladder, the prostatic urethra (bright orange) which is the receptacle of both urinary and seminal contents, orifices of the ejaculatory ducts that are the confluence of the seminal vesicle and the vas deferens, the 15-20 orifices of the prostatic ducts, and finally the small orifices of the ducts of Cowper’s gland which empty into the region of the penile urethra.

Courtesy Ashley Davidoff Copyright 2011 42707b03b45b052prcL02.9s

Magnified View of the Ductal Orifices in the Prostatic Urethra

The diagram reflects a magnified view of the ductal systems involved in the urogenital tract including the internal urethral sphincter, the prostatic urethra (bright orange) orifices of the ejaculatory ducts that lie on the verumontanum, and the 15-20 orifices of the prostatic ducts that lie in the prostatic sinus a type of gutter on the sides of the veru. At the distal end is the external sphincter and finally the small orifices of the ducts of Cowper’s gland which empty into the region of the membranous urethra. The utricle is a small blind ending pouch which is the male equivalent of the uterus.

Courtesy Ashley Davidoff Copyright 2011 99651b18d01.9s

 

Ejaculatory Ducts

The ejaculatory ducts are a paired system that forms by the confluence of the duct of the seminal vesicle and vas deferens.  They enter into the prostatic urethra in the verumontanum just below the prostatic utricle (when present).

Prostatic Urethra

The prostatic urethra is part of the urinary system, structurally characterized by its position in the anterior part of the prostate surrounded by the transitional zone. It is widest in its midportion where the confluence of prostatic ducts, ejaculatory ducts and prostatic utricle are concentrated.  It is a multifunctional conduit for the transport of urine and semen, and in fact is the mixing pot where the major ingredients of semen are combined.