206 ANATOMY OF THE ABDOMEN, ETC. 



DISSECTION VI. 



INTERIOR OF THE PELVIS. 



To examine the interior of the pelvis it is necessary to detach one 

 of the inferior extremities with the corresponding os innorninatum. 

 To do this, the symphysis pubes is to be cut through, leaving the 

 penis and scrotum attached to the side to be preserved ; the saci 

 iliac articulation being found, and its anterior ligaments divided, 

 making the edge of the table a fulcrum and forcibly separatin 

 the divided pubes, the dislocation of the ilium from the sacrum 

 will be effected ; the common iliac and the branches of the internal 

 iliac are to be divided, and the pelvic viscera separated from their 

 lateral attachments on one side only ; then cutting through the sacro- 

 ischiatic ligaments and the gluteus maximus muscle and skin ex- 

 ternally, the limb will be separated and one-half of the pelvis re- 

 main undisturbed. The disadvantage of this method is that one side 

 is necessarily sacrificed. The sacrum may be sawed through upon 

 the median line instead of dislocating the ilium ; the glutei muscles 

 are then left uninjured upon both sides, but the pelvis is not in so 

 favorable a condition for advantageous dissection. 



The position of the pelvic viscera, and the folds of peri- 

 toneum which invest them ma} 7 now be studied. 



It will be seen that the rectum is covered with perito- 

 neum, and held in its place along the middle of the sacrum 

 \)y a mesentery called the meso-rectum ; from the rectum the 

 peritoneum passes over the bladder, leaving a fold between 

 called the recto-vesical fold, and which sometimes forms a 

 tight band or cord-like edge on its posterior surface. If 

 the subject be a female one, we shall have the uterus be- 

 tween the bladder and rectum, and there will then be two 

 folds, the recto-uterine and the vesico-uterine. The lateral 

 reflections of the peritoneum form the false ligaments which 

 sustain the pelvic viscera. It will be noticed that the lower 

 part of the rectum and a large part of the lower half of the 

 bladder have no peritoneal coat, that membrane merely 

 covering them in, and then being reflected to the sides of 

 the pelvis. The point at which it is reflected from the blad- 

 der to the anterior abdominal parietes should be especially 

 examined, to notice the fact that it is possible to perforate 

 the bladder above the pubes without implicating its serous 

 coat. In the female subject the uterus is almost, if not 

 wholly, covered by the peritoneum, and the thickness of 

 the wall between the peritoneal cavity and the vagina, at 

 its union with the neck of the uterus, is so trifling that 



