446 



THE MUSCULATURE 



the penis and their muscles, the bulb of the corpus spongiosum and its muscles, the superficial 

 transverse perinei muscles, and the perineal vessels and nerves (fig. 402). 



Muscle fasciae. — The muscles of the urogenital diaphragm, the urogenital (urethral) sphincter 

 and the transversus perinei profundus, are contained between two fascia layers which constitute 

 the superficial (inferior) and deep (superior) layers of the urogenital trigone (the superficial 

 or inferior and the deep or superior layers of the triangular ligament). 



Fig. 



401. — Section showing the Ischio-rectal Fossa in its Relations to the Pelvic 



Viscera. 



Os pubis 

 Muscles 



Levator ani with its fasciae 

 Obturator internu 



Internal pudic vessels and 

 nerves in obturator fascia 

 Tuber ischii 

 Ischio-rectal fossa with its an- 

 terior and posterior recesses 



Symphysis pubis 



Pubo-prostatic ligaments 

 Prostatic plexus 



Prostate 



Capsule of prostate formed by 



endopelvic fascia 

 Fat 



Rectum invested by erdo- 

 pelvic fascia 



Gluteus maximus 



The superficial (inferior) layer (figs. 392, 394, 400, 402, 403) which lies between the external 

 genitalia and the urogenital diaphragm, is composed of strong bands of fibrous tissue which extend 

 transversely across the subpubic arch and are attached to a ridge on the ischio-pubic rami. It 

 is separated from the arcuate (subpubic) ligament by a mass of fibrous tissue through which the 

 dorsal veins and nerves of the penis (clitoris) run, and in which there is a venous plexus. 



Fig. 402. — Vertical Frontal Section of the Pelvis, showing FASciiE. 

 (Modified from Braune.) 



Orifice of ureter 

 Bladder 



Uvula vesicae 



Levator ani 

 Prostate 

 Colliculus seminalis — 



Levator ani 



Membranous 

 urethra 



Pudic vessels 



Pudic arch 



Fascia of ischio- 



cavernosus 

 Crus penis 



Bulb 



Bulbo-cavernosus 

 with its fascia 

 Integument of 

 perineum 



~ Tendinous arch 



Subperitoneal fat 



Obturator internus 

 t,f^ Ischio-rectal fascia 

 Os innominatum 

 Endopelvic fascia and 



prostatic sheath 

 Obturator fascia 

 Obturator membrane 



Ischio-rectal fossa 

 Superior layer of 



trigone 

 Deep transversus 



perinei 

 Inferior layer of uro- 

 genital trigone 

 Muscles of thigh 

 Ischio-cavernosus 



Muscles of thigh 



Beneath this tissue a fibrous band, the transverse ligament of the pubis, extends between the 

 descending pubic rami. This re{)rosents a region of fusion of the deep and superficial layers of 

 the fuaciiiof tlu; trigone. Posterior to tlic deep triirisvorse niuscle tiie two layers arc likewise 

 fused. The sujjerficial layer is Ix-tlcr devcioixMl in the front than in tlic back part of the space. 

 It is pierced by the urethra (about 3 cm. below the symphysis) l)y the ducts of the bulbo-urethral 



