342 



HISTOLOGY 



.Epithelium. 



.Tunica propria. 



Inner longitu- 

 .-'dinal muscles. 



Circular 

 'muscles. 



Outer longitu- 

 'dinal muscles. 



DUCTUS DEFERENS. 



The ductus deferens begins as a convoluted tube continuous with 

 the ductus epididymidis; it becomes straight and passes to its termin- 

 ation in the ductus ejaculatorius. Shortly before reaching the prostate it 

 exhibits a spindle-shaped enlargement or ampulla about | inch long and f 

 inch wide (Fig. 344). The ductus deferens consists of a mucosa, muscu- 

 laris and adventitia. The epithelium is generally in two rows, the 

 tall inner cells producing round masses of secretion. Toward the epi- 

 didymis it may also have non-motile cilia. Toward the ampulla it may be 



several rowed, resembling the 

 epithelium of the bladder. 

 It rests on a connective tissue 

 tunica propria, which is sur- 

 rounded by the three layers 

 of the muscularis. The inner 

 and outer layers are longi- 

 tudinal and generally less de- 

 veloped than the middle cir- 

 cular layer. The adventitia 

 is a loose elastic connective 

 tissue, blending with that 

 which forms the spermatic 

 The latter contains 

 arteries, veins, 



and nerVCS, tO- 



gether with the striated mus- 



cle fibers of the cremaster muscle, and the rudiment of the processus 

 vaginalis. The veins are very numerous and constitute the pampiniform 

 plexus (i.e., tendril-like). Their walls are usually provided with a very 

 thick musculature including both circular and longitudinal fibers. 



In the ampulla the longitudinal folds, which are low in the ductus 

 deferens, become tall and branched, so that they partly enclose irregular 

 spaces ( dive rticula) . Similar folds occur in the seminal vesicles. It is 

 doubtful whether in either place any of the spaces should be considered 

 glands. Around the ampulla the musculature is irregularly arranged; the 

 longitudinal layers separate into strands which terminate toward the 

 ejaculatory ducts. 



SEMINAL VESICLES ANU EJACULATORY DUCTS. 



The seminal vesicles grow out from the ductus def erentes at the prostatic 

 ends of their ampullae. Each consists of a number of saccular expansions 

 arranged along the main outgrowth, which is irregularly coiled. The 



cord. 

 numerous 



FIG. 343CROSs SECTION OFTHH ; HUMAN DUCTUS DEFERENS. 



