1254 



UROGENITAL SYSTEM 



1. The Testes and Their Appendages 



The scrotum. — The two testes, together with the beginning of the ductus 

 deferentes, are contained within a pouch, the scrotum, which is divided into two 

 compartments by a median sagittal septum, the edge of which is indicated on the 

 surface by a ridge-Uke thickening of the integument, termed the raphe. 



This double condition of the scrotum is explained by its origin from the fusion of two out- 

 pouchings of the lower portion of the abdominal wall, the inguinal canals forming, as it were, 

 the necks of the outpouchings. The testes are primarily retroperitoneal abdominal organs, 

 but later they descend through the inguinal canals into the scrotal outpouchings, where they 

 lie between the peritoneal sac which each of these contains and the remaining layers of the wall, 

 thus retaining their retroperitoneal position. The peritoneal sacs are at first in communication 

 with the abdominal cavity, but after the descent of the testes each undergoes degeneration in 

 its upper part, the cavity disappearing and the peritoneal tissue becoming converted into a 

 portion of the connective tissue in which the ductus deferens and the vessels and nerves asso- 

 ciated with it are imbedded in their course through the s-permatic cord. The portion of the sac 

 in relation with each testis persists, however, and wrapping itself around that structure forms 

 for it a serous investment, the tunica vaginalis propria (fig. 1016). 



The integurnerit oi the scrotum is more or less pigmented and presents numerous 

 transverse ridges extending laterally on either side from the raphe. It is furnished 

 in the adult with coarse, scattered hairs and its sebaceous and sudoriparous glands 

 are well developed. The deeper layers of the dermis, have a pinkish colour, and 

 form what is termed the dartos (fig. 1016), the colouration being due to the 



Fig. 1016. — Horizontal Section of the Scrotum and Testis. (Diagrammatic.) 



Skin 

 Dartos 



Cremasteric fascia 

 Cremaster muscle 



Septum scroti 



Mediastinum testis — >? 



Ductus deferens — 



Parietal layer of tunica vaginalis 



propria 

 Tunica vaginalis communis 



Cavity of tunica vaginalis 



Visceral layer of tunica vaginalis 



propria 

 Tunica albuginea 



Sinus epididymidis 

 Epididymis 



presence in it of numerous non-striated muscle fibres, which are for the most 

 part arranged at right angles to the wrinkles of the surface and are the cause of 

 these. The more superficial fibres of the dartos, like the rest of the integument, 

 form a common investment for both testes, but the deeper ones of either side bend 

 inward at the raphe and assist in the formation of the septum. 



Internal to the dartos and closely related to it is a layer of laminated con- 

 nective tissue, the cremasteric fascia. It is destitute of fat and is continuous at 

 the subcutaneous inguinal ring with the intercrural fibres, being probably the 

 scrotal representative of the external oblique muscle. It is succeeded by a 

 strong sheet of fascia containing longitudinal bands of striated muscle tissue, 

 forming what is termed the cremaster muscle (figs. 389, 1016) and being con- 

 tinuous above with the fibres of the internal oblique muscle of the abdomen. 

 Internal to this is a thin layer of connective tissue, the tunica vaginalis communis, 

 which is continuous with tlie transvcrsalis fascia at the inguinal ring, and, finally, 

 there is the tunica vaginalis propria, which forms the serous investment of the 

 testis and, as has been statcul, is of pcTitoneal origin. Like other similar serous 

 investments it has the; form of a doubU; sac, the outer or parietal layer of which is 

 closely aflhcrcnt to the tunica vaginalis communis and contains numerous non- 

 striped muscle fibres forming what has been termed the internal cremaster 

 muscle. The inner or visceral layer is thinner and closely invests the testis and a 



