UROGENITAL SYSTEM. 



convoluted tube (canal of the epididymis) , about twenty feet 

 long, which forms the chief bulk of the epididymis and ends at 

 the globus minor, by becoming the vas deferens. [1161] 



Vas Deferens. This is a rounded and thick-walled cord, 

 about eighteen inches long, which continues the canal of the 

 epididymis, and begins at the globus minor. It has three 

 coats an outer fibrous, an intermediate muscular, and an 

 inner mucous coat; the lumen is small; it is very tortuous at 

 first, but less so later on. It ascends at first on the inner side 

 of the epididymis, behind the testis, to enter the spermatic 

 cord in which it becomes the most posterior structure. Then 

 running upward in this to the pubic spine and through the ex- 

 ternal abdominal ring, it traverses the inguinal canal, lying in 

 the upper grooved surface of Poupart's ligament. At the in- 

 ternal abdominal ring it leaves the cord, turns round the deep 

 epigastric artery on its outer and posterior aspect, and runs 

 backward, upward, and inward under the peritoneum to cross 

 the ileo-pectineal line nearly two inches from the pubic spine 

 and enter the pelvis. [1162] 



It then runs backward and slightly downward, under the 

 peritoneum, on the pelvic wall toward the ischial spine, cross- 

 ing over the obliterated hypogastric artery, obturator nerve 

 and vessels, vesical vessels, and ureter. Beyond the latter it 

 bends, runs downward and inward, just in front of the pos- 

 terior false ligament of the bladder, to the interval between 

 the rectum and base of the bladder, and approaching the other 

 ureter becomes tortuous and dilated (ampulla) between the 

 seminal vesicles. The ampulla, which is thin-walled, soon con- 

 tracts to a narrow canal, which joins the duct of its seminal 

 vesicle, forming the common ejaculatory duct ; this runs through 

 the prostate, behind the middle lobe and very close to the op- 

 posite duct, and opens into the first part of the urethra by a 

 slit-like aperture lying beside the sinus pocularis. [1163] 



Seminal Vesicles. These lie between the bladder and the 

 recto- vesical pouch and rectum, with their upper and posterior 



[237] 



