312 



DISSECTION OF THE ABDOMEN. 



large 

 intestine : 



transverse 

 meso-colon 



phrenico- 

 colic fold ; 



pelvic 

 meso-colon 



sometimes 

 an ascend- 

 ing or 

 descending 

 meso-colon, 

 or meso- 

 csecum. 



Meso- 

 appendix. 



Appendices 

 epiploicae 



Peritoneal 

 covering of 

 small intes- 

 tine. 



Peritoneum 

 on duode* 

 num. 



Mesentery : 

 form 



attach- 

 ments. 



their relations (pp. 301 et seq.). The following processes pass between 

 the large intestine and the abdominal wall : 



The transverse meso-colon (fig. 114, m c] extends from the anterior 

 ' or lower border of the pancreas to the transverse colon, to the left of 

 the spot where the latter crosses the duodenum, and contains the 

 middle colic vessels. In the adult it is formed by a continuation of 

 the layers of the great omentum, but in the foatus it was a separate 

 mesentery for the bowel. 



The upper end of the left colon has a distinct fold phrenico-colic 

 or costo-colic, fixing it to the wall of the abdomen. Attached by a 

 wide end to the diaphragm opposite the tenth and eleventh ribs, it 

 passes transversely inwards to the colon, and forms the lower boundary 

 of a hollow in which the spleen rests. 



The pelvic meso-colon is a long process of the serous membrane, 

 ' which attaches the loop of the intestine to the wall of the pelvis : 

 it contains the sigmoid and superior hsemorrhoidal vessels. 



In some bodies the ascending and descending colon are surround i>d 

 by peritoneum, which meets behind the gut and forms a fold 

 the ascending or descending meso-colon, between the bowel and the 

 abdominal wall. The csecum may also be provided with a similar 

 fold (meso-ccecum) attaching it to the right iliac fossa. 



The meso-appendix will be seen by lifting up the csecum, and is a 

 fold attached on the one hand to the vermiform appendix, and on 

 the other to the adjacent part of the csecum and the lower surface of 

 the mesentery near the termination of the ileuin. 



Small processes of the peritoneum are attached along the tube of 

 the great intestine, chiefly to the transverse and pelvic colon ; they 

 are the appendices epiplotcce, and contain fat. 



FOLDS TO THE SMALL INTESTINE. The small intestine is not 

 enveloped by the peritoneum after the same manner throughout. 

 For while the jejunum and ileuin are attached to the abdominal wall 

 by one process (mesentery), the .duodenum has special relations with 

 the serous membrane. 



Serous covering of the duodenum. The first part of the duodenum 

 has peritoneal relations like those of the stomach, but its posterior 

 or left surface is only covered for a short distance by the serous 

 membrane. The second part is concealed in front by the converging 

 layers of the transverse meso-colon. The third part, which crosses 

 the aorta, is separated from the peritoneum in the middle line 

 by the superior mesenteric vessels, but is covered in front by the 

 serous membrane on each side of them. The root of the mesentery 

 comes off from the front of the fourth part, which is closely invested 

 by peritoneum on the left side and partly in front. 



Fold of the Jejunum and ileum. The mesentery supports the rest of 

 the small intestine, and is stronger than any other piece of the 

 serous membrane. Its hinder end is narrow, and is attached along 

 the front of the spine and great vessels from the left side of the 

 second lumbar vertebra to the right sacro-iliac articulation (fig. Ill, 

 p. 303 ; the attachment being shown by a line interrupted with short 



