Fig. 150. Male Pelvic Organs, exposed from behind. 



Male aged }^. The Ghiteus Maximus is detached from the Posterior Inferior 

 Iliac Spine downwards and the Erector Spinae divided transversely at thin 

 level. The Sacrum has been sawn through between the 2nd and p-d Sacral 

 Foramina, the Coccyx between the Jst and srid Segments ; the different layers 

 liave then been successively exposed: Rectum, Bladder, Peritoneum, Vas Deferens, 

 Seminal Vesicle and Ureter. On the right side the Great Sacro-Sciatic Liga- 

 ment has been cut short and the Ischiorectal Fossae cleared out on both sides. 



The figure particularly shews the different layers through which the 

 Surgeon cuts in order to reach the Rectum or deeper parts. 



Removal of the lower part of the Sacrum can be carried out, as shewn 

 in the figure, without any great damage. The nerve supply of the Rectum and 

 Bladder is chiefly derived from tlae 3rd Sacral Nerve. There is no risk of opening 

 the Dural Sac which usually terminates at the lower part of the 2nd segment of 

 the Sacrum. Deep to the Sacrum lie the middle and lateral Sacral Vessels; next 

 the Rectal Fascia (yellow) and before reaching the longitudinal muscles of the 

 Rectum a thick layer of fat, in which lie the Superior Haemorrhoidal Vessels and 

 the Lymphatic Glands of the Meso-Rectum, has to be divided. According to the 

 degree of distension the Rectum may occupy the whole of the Recto- Vesical Pouch 

 or leave on either side a peritoneal space (light -blue). The lower boundarj' at 

 which the peritoneum is reflected on the Rectum is about 3 inches above the 

 Anus. Below this level operations on the Rectum can be performed without 

 opening the Peritoneum. 



In front of the Rectum merely separated by Recto-Vesical Fascia is the 

 Bladder, the base of which is laterally and inferiorly covered by the Ampulla of 

 the Vas Deferens and the Seminal Vesicles. In the angle between these struc- 

 tures lies the Ureter (green), this can be exposed by removing a layer of fatty 

 tissue rich in the vascular anastomoses of the numerous branches of the Inferior 

 Vesical Vessels (cf. Fig. 161). 



The arrangement of the muscles bounding the Ischio-Rectal Fossa is to 

 be seen as well as their relation to the lesser Sacro-Sciatic Ligament and the 

 Coccygeus Muscle; a small gap engages one's attention (through which a Hernia 

 of the Floor of the Pelvis may occur), next the Levator Ani Muscle and finall}- 

 the External Anal Sphincter (cf. Fig. 153). 



The Internal Pudic Vessels and Nerve wind round the Spine of the 

 Ischium and run under cover of the Obturator Fascia forwards and downwards. 

 These structures therefore do not re-enter the pelvis through the Sciatic Foramen 

 as usually stated but remain separated by the muscular floor of the pelvis. Neither 

 do these structures pass into the Ischio-Rectal Fossa but remain in Alcock's 

 Canal which is a re-duplication of the Fascia covering the Obturator Internus 

 Muscle on the outer wall of this fossa. 



