244 THE LIVER. 



internal coat, presents a honey-comb appearance. It is covered 

 with columnar epithelium. The mucous membrane of the cystic 

 duct forms folds which bear some resemblance to the valvulse 

 conniventes of the small intestine. These folds are called valvula 

 Heisteri or the valve of Heister. The mucous membrane is con- 

 tinuous with that lining the hepatic and common bile-duct. 



Bile. This is one of the products of the cells of the liver ; 

 as it is secreted it passes through the hepatic and cystic ducts into 

 the gall-bladder, where it is stored until needed at the time of 

 intestinal digestion, when it is discharged through the common 

 bile-duct into the duodenum by an opening common to it and the 

 pancreatic duct. 



Properties of Bile. The bile is a constant secretion i. e., the 

 liver-cells are constantly producing it, although it leaves the liver 



FIG. 138. View of duodenum and pancreas. The part of stomach removed 

 is indicated by dotted lines: A, quadrate lobe: B, right kidney; C, C", right and 

 left suprarenal capsules; D, left kidney; E, pancreas; F, upper part of stomach; 

 (?, spleen; H, duodenum, with a, b, c, d, e. its five parts; /, jejunum; K, duodeno- 

 jejunal angle. 1, lower end of esophagus; 2. pyloric orifice; 3, celiac axis; 4, 

 coronary artery; 5, hepatic artery; 6, Spigelian lobe of liver; 7, 7', splenic ves- 

 sels; 8, left gastro-epiploic artery; 9, right gastro-epiploic artery; 10, superior 

 mesenteric vessels; 11, portal vein; 12, hepatic duct; 13, cystic duct; 14, gall- 

 bladder; 15, left crus of diaphragm; 16. aorta; 17, vena cava inferior; 18. inferior 

 mesenteric vessels; 19, spermatic vessels (Testut). 



intermittently, being forced out by the contraction of the muscular 

 tissue in the walls of the bile-ducts. Some authorities state that 

 it flows continuously into the intestine. But whether this is so 

 or not. the greater part is stored up in the gall-bladder during the 



