THE LIVER 231 



portion of the lesser curvature. The right cord passes to 

 the stomach in a similar manner from the dorsal surface 

 of the oesophagus. These relations suggest the twisting 

 which the stomach has undergone in developing its adult 

 form and position. 



5. Cut across the stomach at the pyloric antrum. Divide the 

 oesophagus, and remove the stomach from the body. Open the 

 organ by means of an incision extending around the greater 

 curvature to the oesophagus. 



On the cut end of the pyloric antrum the mucous and muscular 

 tunics (cf. Fig. 16) may be distinguished and separated from each 

 other by dividing the loose tissue of the tela submucosa. On the 

 surface of the mucous tunic may be seen the gastric areas (areae 

 gastricae), formed by the longitudinal folds and imperfect trans- 

 verse ridges which tend to connect them. They are well marked 

 only in the contracted condition of the stomach. The mucous tunic 

 of the stomach is sharply differentiated from that of the oesophagus. 



IV. THE LIVER 



The liver (hepar) is noteworthy, first, as being the largest of the 

 glandular structures of the body, and, secondly, as containing, in 

 addition to the primary circulation formed by the hepatic artery 

 and veins, the ramifications of the portal system. It is an appen- 

 dage of the digestive tube, its connection with the latter being 

 through the common bile duct, which marks the point at which it 

 developed as an outgrowth from the embryonic endodermal canal. 



For the general relations of the liver, see pp. 94, 95, and following pages. 



1. Examine the contour and plan of division as follows: 



(a) The anterior surface is convex, applied to the diaphragm: 

 the posterior surface is concave, fitting the convexity of the 

 stomach. The organ is thickened in its dorsal portion and 

 tapers to a thin posteroventral margin. 



(b) The liver is partially divided by a deep median cleft into 

 right and left lobes and each of these comprises distinct 

 anterior and posterior lobules. Variable indications of 

 further subdivision sometimes appear, particularly in the 



