490 



THE MUSCULAE SYSTEM. 



The pelvic floor, tense in its anterior part and flexible posteriorly, is formed 

 behind the symphysis pubis by, successively, (1) the fasciae of the urogenital 

 diaphragm and the transversus perinei profundus and sphincter muscle of the 

 membranous urethra between them, the latter enclosing the urethra; and the 

 vagina in the female. (2) The perineal body. (3) The levator ani and external 

 sphincter of the anus on each side of the anal canal; (4) the ano-coccygeal body, 

 between the anal canal and the coccyx, containing the main insertions of the 

 levatores ani and external sphincter. 



Hypogastric vessels 



Vesieula seminalis 

 Rectal channel ' 



Recto-vesical layer of pelvic fascia 

 Ductus deferens 

 ; Anal canal 





Obturator foramen 



Suspensory ligament 

 of prostate 



Lateral pubo-prostatic ligament 



Tendinous arch of pelvic fascia 



Prostate 

 Median pubo-prostatic ligament 



Cavum Retzii Urethra 



FIG. 434. RELATIONS OF THE PELVIC FASCIA TO THE RECTUM AND PROSTATE. 



The levator ani muscle completes the concave floor of the pelvic cavil 

 sweeping downwards and backwards from its lateral wall, so as to form 

 muscular diaphragm, with an intra-pelvic and a perineal surface. Its superic 

 concave pelvic surface occupies the lateral part of the pelvic floor. Its inferi( 

 convex surface forms the oblique medial wall of the ischio-rectal fossathe, lat 

 wall of which is formed by the obturator fascia covering the pelvic surfa 

 of the obturator internus. In this wall is a fascial sheath containing tl 

 pudendal vessels and nerve. The levator ani is covered on both surfaces by pel 1 

 fascia. The anal fascia clothing its perineal surface is thin and unimportant 

 The fascia covering its intra-pelvic surface is thick and strong. At the orij " 



