OF THE PERINJEUM. 



463 



by the Transversus perinsei. The floor of this space is formed by the triangular 

 ligament of the urethra (deep perineal fascia), and running from behind forward 

 in it are the superficial perineal vessels and nerve, and the transverse perineal 

 artery coursing along the posterior boundary of the space on the Transversus 

 perinsei muscle. 



The Triangular Ligament (Deep perineal fascia) is a dense membranous lamina, 

 which closes the front part of the outlet of the pelvis. It is triangular in shape, 

 about an inch and a half in depth, attached above, by its apex, to the under 

 surface of the symphysis pubis and subpubic ligament ; and on each side to the 

 rami of the ischium and pubes, beneath the crura penis. Its inferior margin, or 

 base, is directed toward the rectum, and connected to the central tendinous point 

 of the perinseum. It is continuous with the deep layer of the superficial fascia 

 behind the Transversus perinaei muscle, and with a thin fascia which covers the 

 cutaneous surface of the Levator ani muscle (anal or ischio-rectal fascia). 



GREAT SACRO- 

 SCIATIC LIGAMENT 



Superficial perineal artery. 

 Superficial perineal nerre. 

 Internal pudic nerve. 

 Internal pudic artery. 



FIG. 299. The superficial muscles and vessels of the perinaeum. 



The Triangular ligament is perforated by the urethra, about an inch below the 

 symphysis pubis. The aperture is circular in form, and about three or four lines 

 in diameter. Above this is the aperture for the dorsal vein of the penis ; and, 

 outside the latter, branches of the pudic nerve and artery pierce it. 



The triangular ligament consists of two layers, superficial or inferior, and deep 

 or superior ; these are separated in front, but united behind. 



The superficial layer on its inferior surface is intimately connected with, and 

 sends an expansion to, the bulb. It is pierced by the duct of Cowper s gland and 

 by the membranous urethra ; as is also the following layer. 



The deep layer is derived laterally from the obturator fascia ; 1 superiorly 

 expansions from it are given off into the sheath of the prostate gland, this sheath. 

 in its turn, being formed from the recto-vesical fascia. 



Structures between the Two Layers of the Triangular Ligament. If the 

 superficial layer of this fascia is detached on either side, the following structures 



1 "On the Anatomy of the Posterior Layer of the Triangular Ligament," see a paper by Mr 

 Carrington, Guy's Hospital Reports. 



