1066 



SURGICAL ANATOMY OF THE PERINEUM. 



It is united to the superior or deep layer behind, but is separated in front by a 

 subfascial space in -which are contained certain structures. 



The inferior layer of the triangular ligament consists of a strong fibrous mem- 

 brane, the fibres of which are disposed transversely, which stretches across from 

 one ischio-pubic ranms to the other and completely fills in the pubic arch ; it is 

 attached in front to the subpubic ligament, except just in the centre, where a small 

 interspace is left for the dorsal vein of the penis. In the erect position of the body 

 it is almost horizontal. It is perforated by the urethra in the middle line, and on 

 each side of the urethra! opening by the ducts of Cowper's glands and by the 

 arteries of the bulb ; in front, and external to this, by the artery of the corpus 

 cavernosum, immediately before this vessel enters the crus penis. Near its apex 

 the ligament is perforated by the termination of the pudic artery and by the dorsal 

 nerve of the penis. The crura penis are exposed, lying superficial to this liga- 

 ment. They will be seen to be attached by blunt-pointed processes to the rami of 

 the os pubis and ischium, in front of the tuberosities, and passing forward and 

 inward, joining to form the body of the penis. In the middle line the bulb and 

 corpus spongiosum are exposed by the removal of the Accelerator urinae muscle. 



GREAT SACRO- 

 SCIATIC LIGAMENT. 



Superficial perineal artery. 

 Superficial perineal nerve. 

 Internal pudic nerve. 

 Internal pudic artery. 



FIG. 591. -The superficial muscles and vessels of the perinacum. 



If the superficial layer of the deep perineal fascia is detached on either side, 

 the deep perineal interspace will be exposed and the following parts will be seen 

 between it and the deep layer of the ligament : the subpubic ligament in front, 

 close to the symphysis pubis ; the dorsal vein of the penis ; the membranous 

 portion of the urethra and the Compressor urethrae muscle ; Cowper's glands and 

 their ducts ; the pudic vessels and the dorsal nerve of the penis ; the artery and 

 nerve of the bulb and a plexus of veins. 



The superior layer of the triangular ligament, or deep perineal fascia, is derived 

 from the obturator fascia, and is continuous with it along the pubic arch. Behind, 

 it joins with the superficial layer of the triangular ligament, and is continuous 

 with the anal fascia. Above it is the prostate gland, supported by the anterior 

 fibres of the Levator ani, which act as a sling for the gland and form the Levator 

 prostatse muscle. The superior layer of the triangular ligament is continuous 



