468 LABORATORY MANUAL OF HUMAN ANATOMY 



meeting at its superior border. The double layer of peritoneum 

 thus formed, passing between the stomach and the transverse 

 fissure of the liver, is called the lesser or gastrohepatic omentum 

 (omentum minus). 



Lesser Omentum (Omentum minus). (Figs. 241, 245, 246.) 



Examine the thickened right border, the hepatoduodenal liga- 

 ment (ligamentum hepatoduodenale) ; the remaining portion is 

 sometimes referred to as the hepatogastric ligament (ligamen- 

 tum hepatogastricum). 



How many layers of peritoneum help to form this lesser 

 omentum! What relation do these layers bear to the different 

 peritoneal cavities! From which primitive mesentery is the 

 omentum minus derived! 



Mesentery (Mesenterium). (Fig. 252.) 



What is the length of attachment to the posterior abdominal 

 wall ! This attachment is called the root of the mesentery ( radix 

 mesenterii). What is the length of the attachment to the bowel! 

 What is the greatest length between its two attachments ! 



Note carefully between which vertebrae the mesentery ex- 

 tends; also its general direction. It divides the abdominal 

 cavity (cavum abdominis) into an upper right and a lower left 

 compartment. (Cf. Waldeyer's Kolon nischen.) 



Determine the relation of the radix mesenterii to the pancreas 

 and to the terminal portion of the duodenum. (Vide Poirier et 

 Charpy, t. iv., Fig. 494; Spalteholz, Fig. 563.) 



Mesocolon (Mesocolon). 



(a) Ascending mesocolon (mesocolon ascendens). It is found in only 

 twenty-six per cent, of the cases in the adult. (Treves.) How do 

 you explain its absence in the remaining seventy-four per cent., 

 while it is constantly present in the embryo? For a discussion 

 concerning the factors leading up to the disappearance of these 

 different peritoneal folds and the fixation of organs previously 

 mobile, see Poirier et Charpy, 2 ed., t. iv., Fig. 498. What 

 is Toldt's theory? What are the "fasciae of fusion"? Read 

 about the relation of this fascia to the head of the pancreas, 

 the right kidney, and the right ureter. What is the fascia of 

 Treitz? From what is it derived and what relation does it bear 

 to the head of the pancreas ? 



(fc) Transverse mesocolon (mesocolon transfer sum}. Note the general 

 direction of this mesocolon. How many layers of peritoneum form 

 this fold, and to which peritoneal sac does each belong? Is the 

 arrangement in the adult the same as in the embryo? Determine 



