48 THE POCKET ANATOMY 



the fascia joins the obturator membrane, its bony attachment 

 being here interrupted, and forms thus the floor of the short 

 canal which transmits the obturator vessels and nerve. The 

 upper part of the fascia is in the pelvic cavity, and is lined 

 by peritoneum, whilst the lower part forms the outer boundary 

 of the ischio-rectal fossa, and encases the internal pudic 

 vessels and pudic nerve as they pass forwards. 



(b) The Fascia of the Pyriformis is the continuation of the 

 obturator fascia to the sacrum, and lies anterior to the pyri- 

 formis and sacral plexus. 



Visceral Layer. The Recto-vesical Fascia is attached in front 

 to the posterior surface of the pubis, close to the obturator 

 fascia, the origin of the levator ani intervening. Laterally 

 it is attached to the obturator fascia along a line from the 

 upper part ol the thyroid foramen to the ischial spine, whilst 

 behind it joins the lower part of the pyriformis fascia. From 

 these attachments it passes downwards and inwards over the 

 upper surface of the levator ani to the prostate, bladder and 

 rectum, joining the fascia of the opposite side in front of the 

 bladder, and between the bladder and the rectum, thus form- 

 ing the floor of the pelvis. Along the attachment of the recto- 

 vesical to the obturator fascia is a thickened band, the white 

 line of the pelvic fascia. 



Processes from the recto-vesical fascia : 



Pubo -pro static ligaments or anterior true ligaments of the bladder. 

 Narrow fasciculi, one on each side, passing from the back 

 of the pubes to the front of the prostate and neck of the 

 bladder. 



Lateral true ligaments of the bladder. This is the anterior 

 ligament prolonged laterally, and passes to the side of the 

 prostate, and to the side of the bladder above the vesiculae 

 seminalis, enclosing the prostatic plexus, whilst posteriorly it 

 is attached to the bladder between the vesiculae, and is pro- 

 longed downwards over and enclosing them, being joined to 

 a like process from the opposite side. 



Ligament of the rectum. A piece of fascia descends from the 

 ischium and is attached to the rectum on each side. 



In the female the vagina receives a prolongation of the 

 recto-vesical fascia corresponding to the prostatic sheath. 



Sphincter ani externus : tip and back of coccyx and sub- 

 cutaneous fatty layer on either side(TF) central perineal 

 tendon(F) (4th sacral and inferior haemorrhoidal of pudic). 

 [Closes anus.] 



Sphincter ani internus : the involuntary muscular fibres of 

 the large intestine thickened about \ inch deep. [Closes anus.] 



