24 DISSECTION OF THE DOG 



porta of the liver. Here once again the layers separate, this time to form the 

 serous investment of the liver. The continuation of the most ventral layer 

 of- the lesser omentum follows the caudal surface of the liver, crosses its ventraj 

 border and proceeds to the diaphragmatic surface, from which it is reflected 

 onto the diaphragm, and thence can be followed along the ventral wall of the 

 abdomen to the pelvis. The more dorsal of the two layers of the lesser 

 omentum, in like manner, is continued onto the liver and from this organ to 

 the diaphragm and the dorsal wall of the abdomen. , 



If the two dorsal layers of the greater omentum are followed towards the 

 dorsal wall of the abdomen, they will be found to enclose the left limb of the 

 pancreas before arriving at the wall itself. On the wall the two layers separate. 

 One becomes confluent with the continuation of the more dorsal layer of the 

 lesser omentum. The other passes into the transverse mesocolon ; that is to 

 say, it leaves the dorsal abdominal wall, surrounds the transverse colon and 

 again returns to the wall of the abdomen. Here it is continuous with the root 

 of the mesentery (radix mesenterii). 



Beyond this point the peritoneum proceeds along the abdominal wall into 

 the pelvis and finally becomes that part of the membrane already followed 

 along the ventral abdominal wall. 



From what has just been said, it is clear that a compartment of the peritoneal 

 cavity is enclosed within the greater omentum. Consequent upon its associa- 

 tions, this is known as the omental bursa (bursa omentalis) . The communication 

 between the main peritoneal cavity, entered when the abdomen was first 

 opened, and the omental bursa, is by means of a comparatively small orifice, 

 the epiploic foramen of Winslow (foramen epiploieum [Winslowi]). To find the 

 foramen, pull the duodenum over towards the left and look for the caudate 

 process of the liver, which will be readily recognised as that part of the liver 

 which is in contact with the right kidney. If now the index finger of the left 

 hand be passed along the caudate process towards the middle fine it will enter 

 the epiploic foramen. The right hand should be introduced into the omental 

 bursa through an opening in the omentum, and the epiploic foramen sought 

 from the left side. 



The greater part of the omental bursa is contained in that part of the 

 greater omentum which covers the intestine. The rest of it is continued 

 dorsal to the stomach, and between this organ and those two dorsal layers of 

 the omentum which contain the left limb of the pancreas. The boundaries 

 of the bursa are formed as follows : Venteilly, by the ventral layers of the 

 omentum, by the stomach, by the lesser omentum, and by the omental process 

 of the liver ; dorsally, by the dorsal layers of the greater omentum and the 

 pancreas ; on the left, by the spleen and the gastro-lienal ligament (ligamentum 

 gastro-lienale) which connects the greater curvature of the stomach and the 

 hilus of the spleen, and is directly continuous with the ventral layers of the 

 greater omentum. 



