PARTS WITHIN THE PELVIS. 1077 



the white band stretching from the symphysis pubis to the spine of the 

 ischium, which marks the level at which the pelvic fascia splits into the 

 recto-vesical and obturator fasciae ; while in the upper part of the obturator 

 foramen the obturator vessels and nerve will be seen issuing from the 

 interior. If the ischio-rectal fossa be now thoroughly cleaned, a complete 

 view of the layers of fascia will be obtained, and of their relation to the 

 levator ani muscle (p. 260). The brim of the pelvis is next to be sawn 

 through near the symphysis pubis, on the side on which the dissection has 

 been made, and is to be removed. By this means, if the subject be a male, 

 the relations of the fascia to the prostate gland will be better seen. The 

 ureters and the vasa defereiitia are to be followed as far as the bladder ; the 

 sympathetic nerves of the hypogastric plexus are to be traced in their dis- 

 tribution to the pelvic viscera (p. 702) ; and the branches of the internal 

 iliac vessels are to be dissected. The internal iliac artery will be found to 

 give off to the walls of the pelvis and to the external parts, the gluteal, ilio- 

 lumbar, and lateral sacral arteries, constituting the branches of its posterior 

 division ; the obturator, internal pudic, and sciatic arteries in connection 

 with its anterior division : while to the viscera it supplies the superior 

 vesical with the obliterated hypogastric artery, the inferior vesical giving 

 the middle hsemorrhoidal, and, in the female, the uterine and vaginal 

 arteries (p. 420). The first group may perhaps be best seen on the entire 

 side, and the second and third group on the dissected side of the pelvis. 

 On the former side the sacral nerves are to be displayed (p. 268), and the 

 origin of the pyriformis muscle examined. The junction of the luinbo- 

 sacral cord with the anterior divisions of the three first sacral nerves and a 

 branch of the fourth, to form the sacral plexus, will now be brought into 

 view (p. 669). The gluteal nerve will be found arising from the lumbo- 

 sacral cord (p. 667) ; and arising from the sacral plexus will be found the 

 great and small sciatic nerves, the pudic nerve, the nerve to the obturator 

 internus muscle, and other muscular branches (p. 670). The remaining 

 branches of the fourth sacral nerve will be found to aid the hypogastric 

 plexus in the supply of nerves to the viscera : at the same time the small 

 fifth sacral and coccygeal nerves may also be dissected (p. 668). The 

 coccygeus and levator ani muscles are to be cleaned on their upper aspects, 

 when they will be seen to form a continuous muscular floor to the pelvic 

 cavity (p. 262). Tbe chains of sympathetic ganglia are then to be dissected 

 in front of the sacrum, and, if possible, the lowest parts traced to their 

 junction in front of the coccyx (p. 696). 



9. Pelvic Viscera. It may be proper to examine the muscular walls of 

 the bladder in the inflated condition of the organ, before its removal from 

 the pelvis (p. 944) ; after which the viscera are to be separated from their 

 attachments to the walls of the pelvis, and removed in one mass. 



The rectum may then be carefully dissected away from the rest of the 

 viscera, the extent of its connection with them being at the same time 

 observed (p. 856). Its muscular coats having been sufficiently examined, it 

 is to be slit open and washed, in order that the general appearance and folds 

 of its mucous membrane may be seen. In the male subject the prostate 

 gland enveloped in its fibrous covering, the vesiculae seminales, and the vasa 

 deferentia are to be carefully dissected (pp. 952 and 971) ; the bladder 

 is to be opened from before, the neck being left in the first instance entire ; 

 and the openings of the ureters and urethra, with the trigone between 

 them, are to be examined (p. 948). The prostatic, membranous, and bulbous 

 parts of the urethra are then to be slit open from above, the varying dia- 



