THE PERITONEUM 



1253 



from the left leaf. This omental sac or greater omentum extends downward as an 

 apron-like fold in front of the transverse colon and the coils of the small intestine. 

 The anterior layer of the transverse mesocolon is at first quite distinct from the 

 posterior layer of the bursa omentalis, but ultimately the two blend, and hence the 

 greater omentum appears as if attached to the transverse colon (Figs. 974, 975, 

 and 976). 



The lesser omentum is formed by a thinning of the mesoderm of the ventral 

 mesogastrium which attaches the stomach and part of the duodenum to the ventral 

 abdominal wall. By the subsequent growth of the liver this leaf is divided into 

 two parts viz., the falciform and coronary ligaments between the liver and the 

 abdominal wall and Diaphragm; and the lesser or gastrohepatic omentum, be- 

 tween the liver and the stomach. 



Aorta. 



Spleen. 



Mesogastrium. 

 Coeliae axis. 



Pancreas. 



Anterior part of mesogastrium. 



Superior mesenteric 

 artery. 



Mesentery. 



Inferior mesenteric artery. 



Hind gut. 



FIG. 977. Abdominal part of alimentary canal and its attachment to the primitive or common mesentery. 

 Human embryo of six weeks. (Kollmann.) 



Vertical Disposition of the Greater Sac (Fig. 979). It is convenient to trace the 

 greater sac from the back of the abdominal wall at the level of the umbilicus. 



On following the parietal peritoneum upward from this level it is seen to be 

 reflected around a fibrous cord, the ligamentum teres or impervious umbilical vein 

 (Figs. 982 and 1067), which reaches from the umbilicus to the under surface of 

 the liver. This reflection forms a somewhat triangular fold, the falciform or 

 suspensory ligament of the liver (ligamentum falciforme hepatis), attaching the 

 upper and anterior surfaces of the liver to the Diaphragm and abdominal wall. 

 With the exception of the line of attachment of this ligament the peritoneum 

 covers the whole of the under surface of the anterior part of the Diaphragm and 

 is continued from it on to the upper surface of the right lobe of the liver as the 

 superior layer of the coronary ligament, and on to the upper surface of the left 

 lobe as the superior layer of the left lateral ligament of the liver. Covering the 

 upper and anterior surfaces of the liver it is continued around it? sharp margin 

 on to its under surface, where it presents the following relations: (a) It covers 



