1148 DIGESTIVE SYSTEM 



splenic ligament, and once more reaches the spleen. It passes right around the spleen to 

 the back of the hilus, where it is reflected on to the left kidney as the lieno-renal hgament 

 (fig. 903). Hence the peritoneum passes along the side and front of the abdomen to the point 

 from which it started. In this section the liver is so divided as to appear separated from all 

 connection with the other viscera and the abdominal wall, and to be surrounded by peritoneum. 



The course of the peritoneum in a longitudinal section of the body will now 

 be considered (fig. 904). Starting at the umbilicus and passing downward, the 

 peritoneum is seen to line the anterior abdominal wall. Before reaching the pelvis 

 it covers also the urachus, the deep epigastric arteries, and obliterated hypogastric 

 arteries, which form ridges beneath it. For some little way above the os pubis 

 the peritoneum is loosely connected with the abdominal wall, a circumstance 

 which is made use of in supra-pubic cystotomy. Moreover, as the distended blad- 

 der rises from the pelvis it can detach the serous membrane to some extent from 

 the anterior abdominal wall. In extreme distension of the bladder the peritoneum 

 may be lifted up for some 5 cm. vertically above the symphysis. On reaching the 

 OS pubis it is reflected on to the upper part of the bladder, covering it as far back 

 as the base of the trigone; thence it is reflected on to the rectum, wihch it covers 

 in front and at the sides on its upper part, rarely forming a distinct mesorectum. 

 Between the bladder and rectum it forms in the male the recto-vesical pouch. 

 The mouth of this pouch is bounded on either side by a crescentic fold, the plica 

 semilunaris. In the female the peritoneum is reflected from the bladder on to the 

 uterus, which it covers; it then extends so far down in the pelvis as to pass over 

 the upper part of the vagina behind; thence it extends to the rectum. The peri- 

 toneum which invests the uterus is reflected laterally to form the broad ligaments. 

 The fold between the vagina and rectum forms the recto-vaginal pouch, or pouch 

 of Douglas. The membrane has now been traced back to the spine. 



Following it upward, the sigmoid colon will be found to be completely covered 

 by peritoneum, a mesocolon attaching the gut to the abdominal wall (shown 

 in fig. 905). A little higher up in the median line the peritoneum passes forward, 

 to enclose the small intestine, and, returning to the spine, forms the mesentery 

 (fig. 904). It now passes over the third part of the cluodenum to the pancreas, 

 from which point it again passes forward to form the lower layer of the transverse 

 mesocolon. It invests the transverse colon below and partly in front, and then 

 leaves it to pass downward to take part in the great omentum. Running down- 

 ward some distance, it returns and forms the anterior layer of the omentum. On 

 reaching the stomach it goes over the anterior surface, and at the upper border 

 forms the anterior layer of the lesser or gastro-hepatic omentum, which extends 

 between the stomach and the liver. It invests the inferior surface of the liver in 

 front of the transverse fissure, and, turning over its anterior border, covers the 

 upper surface. At the posterior limit of the upper surface it leaves the liver and 

 goes to the diaphragm, forming the superior layer of the coronary ligament. It 

 covers the anterior part of the dome of the diaphragm, and, once more reaching 

 the anterior abdominal wall, can be followed to the umbilicus, where it was first 

 described. This completes the boundary of the greater sac. On reference to the 

 diagram (fig. 904) the student might be led to suppose that the two sacs are quite 

 separate. This, of course, is not the case; but in a longitudinal section of the 

 body made anywhere to the left of the epiploic foramen (foramen of Winslow), 

 it is impossible to show the direct connection between the two sacs. (See fig. 905.) 



The peritoneum has only been traced in this longitudinal section so far as it 

 concerns the greater sac. It now remains to follow upon the same section (fig. 

 904) such part of the membrane as forms the lesser sac. The peritoneum here 

 will be seen to cover the posterior surface of the stomach; thence from the lesser 

 curvature it runs upward to the liver, forming the posterior layer of the lesser or 

 gastro-hepatic omentum. It reaches the liver behind the transverse fissure. It 

 covers only a part of its posterior surface (caudate lobe), and is reflected on to the 

 diaphragm, forming the lower layer of the coronary ligament. It now goes down- 

 ward over the j)ost('rior part of the tlome of the diaphragm to the spine, separated 

 from the latter by the great vessels. On reaching the anterior bortler of the pan- 

 creas it passes forward, and forms the upper lay(T of the transverse mcso-colon. 

 It then covers the u])per half of tlie transverse (H)l()n, and, descending, forms the 

 innermost layer of tlu; great omentum. (The inner layers of the great omentum 

 are usuafly fused in the adult, however, thus obliterating this portion of the lesser 

 sac.) It now ascends, and, arriving at the greater curvature of the stomach, 



