PELVIS 



567 



been demonstrated. The recto- vesical layer must now be incised, in 

 the medial plane, on the posterior surface of the prostate and each 

 half must be turned laterally. As the borders of the prostate are 

 approached a plexus of veins will be exposed on each side, and immediately 

 beyond the plexus the recto- vesical layer of the fascia will be "found to 

 blend with the vesical layer, which passes over the upper surface of the 

 prostate. The ducti deferentes and the seminal vesicles will be exposed 

 when the reflection of the recto-vesical layer is carried backwards beyond 

 the prostate (Fig. 220). 



Crus penis 



Internal pudendal artery 



Bui 

 Urogenital diaphragm 



(inferior fascia) 

 Urogenital diaphragm 

 (superior fascia) 



Prostate - * 



Levator ai 



Seminal vesicle 



Ductus deferens 



scto-vesical fascia 



Rectal fascia 



Rectum 



Levator ani 



llutajus maximus 



Bulbo-cavern osus niusch 



Ischio-cavernosus mus 



Urethra 



Inf. fascia of urog 

 Transversus peri 

 Colics' fascia 



Sphincter ani 

 externus 



FIG. 220. Dissection to expose the Prostate from the Perineum. 



The True Ligaments of the Bladder. There are five so- 

 called true ligaments of the bladder, two lateral, the lateral 

 pubo-vesical ligaments, two anterior, the medial pubo-vesical 

 ligaments, and one superior. The lateral are the lateral parts 

 of the vesical layer of pelvic fascia. The anterior are two 

 thickenings of the same layer, one on each side of the medial 

 plane in front of the bladder; they contain smooth muscle 

 fibres which pass from the bladder to the back of the pubic 

 bones at the margins of the symphysis. The superior, the 

 lig. umbilicale medium, is formed by the urachus. 



During the various stages of this dissection the student 



