THE DEFEKENT DUCT. 



1291 



jrior iliac spine, it enters the abdomen. The distance between the point where 

 the cord enters the inguinal canal to the point where it leaves it to enter the 

 abdomen is about one and a half inches. While passing from the subcutaneous 

 to the abdominal inguinal ring the ductus deferens, together with the other 

 structures of the funiculus spermaticus, rests upon the upper grooved surface 

 of the inguinal ligament, and is placed behind the aponeurosis of the external 

 oblique and some of the lower fibres of the internal oblique muscle. From before 

 backwards the duct rests, in the first instance, upon the falx aponeurotica or con- 

 joined tendon of the internal oblique and transversus abdominis muscles, and farther 

 laterally upon the fascia transversalis. Above the funiculus are some arching fibres 

 of the internal oblique muscle which enter the falx. As the ductus deferens leaves 

 the inguinal canal by the abdominal inguinal ring, it turns round the inferior 



Branches of hypogastric artery 

 Obturator artery 



Right ureter 



Nerve cord from hypogastric plexus 



Obliterated umbilical 

 artery (lig. nmbilicale) 



Plica vesicalis transversa 



Sacro-genital fold 



Vesical arteries ( 



Ductus deferens 



Paravesical peritoneal fossa 



FIG. 1009. MEDIAN SECTION OF THE PELVIS IN AN ADULT MALE. 

 le coils of small intestine and colon which lay within the pelvis have been lifted out in order to give a view 



of the side wall of the pelvic cavity. 



epigastric artery on its lateral and posterior aspect. Completely changing the 

 direction of its course, the duct now runs for a short distance backwards, medially, 

 and upwards, beneath the peritoneum, to a point one and a half to two inches from 

 the pubic tubercle, where it crosses the ilio-pectineal line and enters the pelvis minor. 

 In this part of its course the duct usually lies at first in front of the external iliac 

 vessels, and then in the floor of a little triangular fossa, the trigonum femorale, 

 between these vessels and the pelvic brim (Fig. 1009). On the side wall of the 

 pelvis minor the ductus deferens is continued backwards, and a little downwards and 

 medially, in the direction of the ischial spine, and lies immediately external to the 

 peritoneum, through which it can usually be seen shining. In the pelvic part of 

 its course the ductus deferens crosses on the medial side of (1) the obliterated part 

 of the umbilical artery, (2) the obturator nerve and vessels, (3) the vesical vessels, 

 and (4) the ureter (Fig. 1009). 



