REFLECTIONS OF PERITONEUM. 437 



FOLDS OF THE PERITONEUM. After tracing the continuity of the 

 serous sac over the viscera, the student is to learn the chief processes or 

 folds of the membrane in connection with the alimentary tube. The 

 pieces of the peritoneum fixing the liver will be examined afterwards; and 

 the processes on the viscera of the pelvis will be seen with the dissection 

 of that cavity. 



Folds on the stomach. The processes connected with the stomach are 

 named omenta. They are three in number one, small omentum, is at- 

 tached to the upper curve ; another, great omentum, to the lower curve ; 

 and the third, splenic omentum, is fixed to the great end of the viscus. 



The small or gastro-hepatic omentum is stretched between the under 

 surface of the liver and the upper border of the stomach, and contains the 

 vessels and nerves of the liver. It is formed by two pieces of peritoneum, 

 as before explained, and presents a free border on the right side. Behind 

 it is the space called foramen of Winslow. Its lower edge is fixed to the 

 small curve of the stomach; whilst its upper border is attached to the 

 transverse fissure, as well as to the posterior half of the longitudinal fissure 

 of the liver, blending behind with the left lateral ligament of that viscus. 



The gastro-colic or great omentum is the largest fold of the peritoneum, 

 and consists of two pieces. It is attached above to the spleen and the 

 lower border of the stomach, and descends in front of the large intestine, 

 but lower on the left than the right side of the body. At the lower part 

 of the abdomen the process is bent backwards, and returns to the spine, 

 the pieces of which it is composed separating to inclose the transverse 

 colon. The anterior part of the omental fold is separated from the poste- 

 rior by a space (cavity of the omentum). 



Between its layers are contained some fat, vessels, and nerves; and the 

 power of detaching the one layer from the other diminishes with the in- 

 crease of the distance from the stomach, until below they are not to be 

 separated, and the membrane they form is thin and net-like. 



Cavity of the omentum. When an opening is made through the great 

 omentum near the stomach, and this viscus is raised, a space is seen to 

 extend upwards to the liver, and downwards into the omentum : this is the 

 omental cavity. In front the space is bounded by the small omentum, the 

 stomach, and the anterior part of the great omentum. Behind it, are the 

 posterior part of the great omentum, the transverse colon, and the ascend- 

 ing layer of the transverse meso-colon. This space communicates with 

 the rest of the peritoneal cavity, through a hole (foramen of Winslow), 

 behind the small omentum. 



If the sac of the omentum were perfect, it could be inflated through the 

 foramen of Winslow. Supposing it to be detached and removed, there 

 would not be any membrane in the way of the vessels reaching the differ- 

 ent viscera; and it may be readily conceived how the peritoneum could 

 be replaced over the viscera, and around the vessels without being perfo- 

 rated by them. 



The foramen of Winslow is the space behind the small omentum, 

 through which the omental bag opens into the general cavity of the peri- 

 toneum. In front of it is the small omentum, and behind, are the vena 

 cava and the spine. Above it is the liver (lobulus Spigelii), and below is 

 the duodenum. 



The splenic omentum reaches from the great end of the stomach to the 

 concave surface of the spleen, and does not consist usually of two strata or 



