[Fig. 100].—Liver, Cranial Surface.

a, left lateral lobe; b, left median lobe; c, right median lobe; d, d′, right lateral lobe; e, gall-bladder; f, opening of posterior vena cava, with the smaller openings of the hepatic veins.

[Fig. 101].—Liver turned Craniad, showing Dorsocaudal Surface.

a, left lateral lobe; b, left median lobe; c, c′, right median (or cystic) lobe; d, d′, cranial and caudal divisions of the right lateral lobe; e, caudate lobe; f, gall-bladder; g, cystic duct; h, hepatic ducts; i, common bile-duct; j, portal vein; k, part of duodenum.

The Gall-bladder ([Fig. 101], f) is pear-shaped and lies in a cleft on the caudal (or dorsal) surface of the right median lobe (c, c′) of the liver. Its larger end is directed caudad (or ventrad) and is free. By one surface it is in contact with the liver and not covered by peritoneum, while the other surface is covered by peritoneum. The peritoneum in passing from the larger free end to the liver forms one or two ligament-like folds. By its smaller end the gall-bladder is continuous with the cystic duct (g). This duct is about three centimeters long and has a sinuous course. At its distal end it is joined by two (or more) hepatic ducts (h), bringing the bile from the lobes of the liver. The relation of these to the cystic duct varies. They may open into it by a common trunk or separately. Of these hepatic ducts one is made up by the junction of smaller hepatic ducts from the left half of the liver and the left half of the cystic lobe, while the other is similarly formed by smaller ducts from the right half of the cystic lobe, from both divisions of the right lateral lobe and from the caudate lobe. The duct formed by the junction of the hepatic and cystic ducts is the common bile-duct (ductus communis choledochus) (i). It passes in the free right border of the gastroduodenal omentum to the duodenum (k) and opens into it by way of the ampulla of Vater, in common with the pancreatic duct, at a point on the dorsal surface of the duodenum and about three centimeters from the pylorus.

Pancreas.—The pancreas ([Fig. 102], a) is a flattened, closely lobulated gland of irregular outline, about twelve centimeters long, varying in width from one to two centimeters. It is bent nearly at right angles at about its middle. One of the halves (a′) into which it is divided by its bend lies in the descending limb of the great omentum, and is near the greater curvature of the stomach (d) and parallel to it. The free end of this half is in contact with the spleen (e). The other half (a) lies in the duodenal omentum between the limits of the duodenal U (c) and reaches to the bottom of the U. The pancreas has two ducts. The larger pancreatic duct (b) (sometimes known as the duct of Wirsung) collects the pancreatic fluid from both halves of the gland, the ductlets from each half uniting to make two larger ducts, which then unite near the angle of the gland to make the pancreatic duct. This is short and broad and opens into the ampulla of Vater together with the common bile-duct. The accessory pancreatic duct (duct of Santorini) opens into the duodenum about two centimeters caudoventrad of the ampulla of Vater. It is formed by the union of branches which anastomose with those of the pancreatic duct. It is apparently sometimes lacking.

[Fig. 102].—Pancreas and Spleen.