PELVIS MINOR 425 



ligaments. The vesical layer must now be divided in the median 

 plane and turned laterally to each side. Whilst that is being 

 done it will be noticed that, above the prostate, the vesical 

 layer is gradually lost on the anterior border and infero-lateral 

 surfaces of the bladder (Fig. 199). When the fascia has been 

 turned laterally to its junction with the recto-vesical layer, 

 already displayed from below, the dorsal vein of the penis must 

 be followed backwards. It divides, immediately after entering 

 the pelvis, beneath the vesical layer of fascia, into right and left 

 branches which join the corresponding parts of the pudendal 

 (O.T. prostatic) venous plexus. 



The dissector should notice that, by the removal of the 

 bone in the region of the symphysis, he has exposed not only 

 the structures already noted, but also the whole of the anterior 

 border of the bladder and parts of its infero-lateral surfaces. 

 If he now replaces the pelvic peritoneum, he will find that it 

 has no relation to the border and surfaces mentioned ; they lie 

 entirely below the level of the peritoneum. They form the 

 posterior boundary of the lower part of the cave of Retzius, 

 and lie in relation with the anterior and antero-lateral parts 

 of the pelvic wall, from which they are separated by the 

 extraperitoneal fatty tissue which was removed at an earlier 

 stage of the dissection. The dissector has now seen three 

 surfaces of the bladder the superior surface, covered with 

 peritoneum, and the two infero-lateral surfaces. The bladder 

 possesses also a fourth surface, the fundus or base, which lies 

 in relation with the deferent ducts, the seminal vesicles, and 

 to a less extent with the lower part of the anterior wall of the 

 rectum. That surface and the interior of the bladder should 

 now be investigated. 



Dissection. Enter the knife through the anterior border 

 of the bladder, a little below its upper extremity, and carry it 

 backwards first on one side and then on the other, just below 

 the upper border of each infero-lateral surface. When the 

 incisions have been made, push the upper surface of the bladder 

 backwards and press the infero-lateral surfaces downwards and 

 forwards. An excellent view of the interior will thus be obtained, 

 and, when its surface has been sponged, the mucous lining and the 

 orifices may be examined, and the relations of the base may be 

 investigated. If it is necessary, the anterior border may be 

 divided vertically from the apex of the bladder to the upper 

 border of the prostate. 



Interior of Bladder. The mucous membrane is rugose, 

 when the bladder is empty, over the whole of the inner surface, 

 except a small triangular area on the basal wall (Fig. 200). 

 The rugosity is due to the loose manner in which the 



