Fig. 136. Position of the Abdominal Viscera seen from behind: lines 



of Peritoneal Reflection. 



The plaster model by His which has been made from nature (cf. Archiv. f. 

 Anat. u. Phys., Anat. Abt, 1878) shews when taken to pieces and put together again 

 the form and position of the Abdominal Organs in a beautiful manner; further 

 this model shews the individual relations of the various organs, the lines of 

 reflection of the Peritoneum, and the relations of intra- and extra-peritoneal areae. 



Our figure varies slightly from the model by His (cf. Fig. 130). 



Uncovered by Peritoneum : A considerable area of the posterior surface 

 of the Liver, posterior surface of the Pancreas, of the Duodenum and of both 

 kidneys, the anterior surface of the Kidneys in contact with the Pancreas (cf. 

 F'R- 135 ai^d 139). The large vessels are also extra-peritoneal: — Aorta and 

 Inferior Vena Cava, the posterior wall of the greater part of the Ascending Colon 

 and Descending Colon. The posterior aspect of the middle portion and the whole 

 of the lower portion of the Rectum. The Caecum is also uncovered b}' the peri- 

 toneum except where the Ileum opens into its posterior aspect as it becomes 

 closely applied to the wall of the False Pelvis. 



On rare occasions only does the Caecum possess a Mesenter}- whereas the 

 Vermiform Appendix is enveloped in Peritoneum and has its own Mesentery — 

 Mesenteriolum — . 



The extra-peritoneal position of the Kidneys, Ascending and Descending 

 Colon afford an important means of operating upon these Viscera without opening 

 the peritoneal cavity (cf. Fig. 134). Moreover, as the peritoneum is only loosely 

 attached to the anterior surface of the kidney, it can be easily detached, and thus 

 the kidney removed without opening the peritoneal cavity. 



Formerly, Lumbar Colostomy was frequently performed for disease of the 

 Sigmoid and Rectum. 



The absence of Peritoneum on the posterior surface of the Rectum bears 

 an important'! relation ^° ^^ spread of inflammation. This absence of peritoneum 

 is unfavourable for circular enterorrhaphy after removal of Rectal Carcinoma 

 because gut surrounded by Peritoneum heals more readily. 



