234 



NORMAL HISTOLOGY. 



Fibrous envelope 



Canal of 



epididymis 



mounting the cells. In places the epithelium contains minute tubular diver- 

 ticula that are regarded as abortive glands. Outside the membrana propria 

 the duct is enclosed by a robust circular layer of unstriped muscle (15-30 it 

 thick), which attains its greatest development within the globus minor, near 



the beginning of the vas 

 deferens. The convolutions 

 of the canal are held to- 

 gether and in place by inter- 

 vening fibro-el^stic tissue. 



The blood-vessels 

 supplying the testicle are 

 branches from the spermat- 

 ic and deferential arteries, 

 those from the former being 

 distributed especially to the 

 testis and those from the 

 latter to the epididymis. 

 The spermatic branches 

 enter the mediastinum and 

 break up into superficial 

 and deep twigs that follow 

 the tunica albuginea and the 

 septa respectively. They 

 continue within the tracts 

 of intertubular connective 

 tissue and ultimately form 

 rich capillary networks en- 

 closing the seminiferous 

 tubules, immediately out- 

 side the basement mem- 

 brane. The arteries dis- 

 tributed to the epididymis 

 course within the intertubu- 

 lar stroma and likewise re- 

 solve into capillaries that 

 enclose the efferent ducts and the convolutions of the canal of the epididy- 

 mis. The veins arise from the capillary networks ; those from the testis, 

 superficial and deep, emerge at the mediastinum and, joining with those from 

 the globus major, concentrate into several stems of considerable size that 

 ascend within the spermatic cord in the anterior part of the pampiniform 

 plexus. The veins from the body and tail of the epididymis unite into a 

 smaller group that ascend in the posterior part of the plexus. 



The lymphatics of the testis begin in the connective tissue surround- 

 ing the tubules and follow, in a general way, the course of the veins as a 

 superficial and a deep set. They emerge from the mediastinum as six to 

 eight relatively large trunks, to which the lymphatics of the epididymis are 

 tributary, and accompany the veins in the cord. 



The nerves of the testicle are chiefly sympathetic fibres destined for 

 the walls of the blood-vessels and the unstriped muscular tissue of the epi- 

 didymis. They form plexuses enclosing microscopic ganglia around the larger 

 vessels. The relation between the terminal fibres and the tubules includes 

 epilemmar fibrils on the exterior of the basement membrane and, perhaps, 

 a few hypolemmar ones that penetrate between the epithelial cells. 



eferens 

 FIG. 285. Section across lower part of epididymis. X 15. 



