1162 THE DIGESTIVE SYSTEM. 



viscera lying upon it (Fig. 914). It should be pointed out that all the abdominal 

 viscera are either directly fixed by connective tissue to the posterior abdominal 

 wall, or connected by blood-vessels with it. In the former case the peritoneum is 

 reflected directly from the wall on to the viscera ; in the latter it runs along the 

 blood-vessels to reach the viscera, which it clothes, and then returns to the wall 

 on the opposite sides of the vessels, which it thus encloses in a fold. 



Whilst the greater part of the general peritoneal cavity lies anterior to the 

 various abdominal viscera, covering them over and dipping down between them, it 

 should be mentioned that there is a special diverticulum derived from it, situated 

 mainly behind the stomach, and covering its posterior surface ; this is known as 

 the bursa omentalis (O.T. small sac), and it will be described in detail later. The 

 aperture through which one sac communicates with the other is termed the 

 foramen epiploicum (Winslowi) (O.T. foramen of Window}. 



In passing from organ to organ, or from these to the abdominal wall, the 

 peritoneum forms numerous folds, the principal ones being as follows : 



(1) Omentum Majus. rThe greater amentum hangs down like an apron from 

 the transverse colon, in front of the coils of the jejunum and ileum. It consists 

 embryologically of four layers of peritoneum, two anterior and two posterior, which 

 are usually, in the adult, adherent to one another. The four layers form a thin, 

 translucent, and often perforated membrane. The anterior two layers were origin- 

 ally connected with the stomach above, and passed down in front of the transverse 

 colon, but as development proceeds they become adherent to the anterior surface 

 of the transverse colon. The fold which extends from the stomach to the colon is 

 termed the gastro-colic ligament. If the anterior two layers are separated from the 

 posterior two and from the front of the transverse colon, a cavity is formed, con- 

 tinuous with the bursa omentalis, and the anterior layers of the greater omentum 

 are directly continuous with the layers of the gastro-colic ligament. This condition 

 is that usually described in English text-books as the normal adult condition and 

 is represented in Fig. 914, where the gastro-colic ligament is separated from the 

 transverse colon, and passes in front of the transverse colon directly into the 

 anterior layers of the omentum majus, and the great omentum thus descends from 

 the stomach above. 



(2) Omentum Minus. The lesser omentum is a fold passing from the inferior 

 surface of the liver to adjacent organs. It consists of two, or occasionally three, 

 portions : 



(a) The ligamentum liepatogastricum, a wide peritoneal fold, extending from the 

 left end of the porta hepatis, the fossa of the ductus venosus, and partly also from 

 the concave surface of the left lobe of the liver and the caudate process, to the 

 lesser curvature of the stomach, where it is continued into the peritoneal coats of 

 the anterior and posterior surfaces of that organ. 



(b) The ligamentum hepatoduodenale passes from the porta hepatis to the pars 

 superior of the duodenum. On the left this fold is continuous with the hepato- 

 gastric ligament, on the right it ends in a rounded margin. Traced downwards, 

 the layers of peritoneum which form it clothe the commencement of the 

 duodenum on two sides, and are continued into the transverse mesocolon, and into 

 the duodeno-renal ligament. 



(c) The ligamentum hepatocolicum is an occasional fold passing from the region 

 of the gall-bladder to the transverse colon and right colic flexure. 



(3) Ligamentum Gastrolienale. The gastro-splenic ligament (O.T. gastro-splenic 

 omentum)is a double layer of peritoneum extending between the fundus of the stomach 

 and the hilum of the spleen, and continuous below with the gastro-colic ligament. 



(4) The ligamentum gastrocolicum extends from the greater curvature of the 

 stomach to the transverse colon. It consists of two layers of peritoneum, continuous 

 above with the layers on the anterior and posterior surfaces of the stomach, and 

 below with the anterior layers of the great omentum. 



In English text-books this is not usually recognised as a separate ligament, but 

 is considered to be a portion of the greater omentum, and to pass downwards in front 

 of the transverse colon. It will be found, however, that the arrangement in the 

 adult is usually that described above. 



