Practicum IV. The Liver. 27 



the spleen ; it resembles the thymus (Pract. Ill, 28), or a salivary gland 

 Pract. VI, 3). The general location of its two ducts, by which the pan- 

 creatic liquid is poured into the duodenum, may be recognized from the 

 closer adhesions, but there may be neither time nor light for tracing 

 them in detail ; see Anatomical Technology, Figs. 79 and 81. 



a. The pancreas is naturally pale but may be discolored and dark in the alcoholic 

 specimen. The portion extending toward the spleen is but slightly represented in man. 



17. The Liver. This is more nearly mesal and symmetrical than 

 in man, and more completely subdivided into lobes, permitting greater 

 flexibility of the animal. Note the reflections of its peritoneum upon 

 the diaphragm. 



18. Removal of the Diaphragm. With the scissors cut the 

 diaphragm from all its attachments, (a) at the periphery ; (b) at the peri- 

 toneal reflection upon the liver ; (c} where it is traversed by the esopha- 

 gus, aorta and postcava but without cutting these three tubes. 



19. Tilt the ventral margin of the liver cephalad so as to expose 

 more of the intestine. Note the continuity of the small intestine with 

 the stomach cephalad and with the large intestine (colon); also that the 

 whole length is quite closely connected by mesentery excepting the cau- 

 dal part of the colon. 



20. Detaching the Small Intestine. At any point not less than 10 

 cm. (4 in.) from the cecum cut the mesentery close to the intestine ; con- 

 tinue to cut, first one way and then the other, until within about 5 cm. of 

 the cecum and about 10 cm. of the stomach. At each of these points 

 compress the intestine so as to force the contents either way for 1-2 cm. ; 

 tie firmly with a cord at both ends of the vacated space and cut between. 

 Ask the janitor to remove the detached portion of intestine. 



21. The Gall-Bladder or Cholecyst. This is lodged in a cleft of 

 one lobe of the liver, PI. X, 2, 3 ; if full, compress it steadily until the 

 bile passes through the contorted BILE-DUCT into the duodenum near the 

 attachment of the pancreas. If it is empty slit it and inflate, preventing 

 the escape of air with the fingers ; the air may be made to pass through 

 the duct into the intestine. 



a Remember that the gall-bladder is not a source of bile, but merely a reservoir ; as 

 the bile comes from the substance of the liver through the hepatic ducts a portion of it 

 flows back to the gall-bladder and is there stored up. See Martin, Fig. 52 and Anatomical 

 Technology, Fig. 79. Remove the liver, pancreas and spleen. 



NOTE. The directions in the following paragraph may be disregarded if time is lack- 

 ing or strong objections are felt to following them : 



22. Opening the Stomach. Cut the stomach away together with the 

 attached portions of the esophagus and small intestine. Take it to the 

 sink. Over the water-pail slit with the scissors along the greater curva- 

 ture from the orifice of the esophagus to the end of the duodenum ; press 

 out the contents ; rinse off the mucosa with a stream of water, gently 

 rubbing the surfaces together. When cleansed from food and mucus take 

 the stomach to the table and note the following points : 



a. The gastric mucosa is loosely adherent to the muscular coat. 



b. It may present several RUG-'E, folds or ridges, which permit con- 

 siderable distention of the organ without undue tension of the mucosa. 

 The rugae are usually apparent in fresh specimens, but may be obliterated 

 by distention of the stomach as by the injection of alcohol. 



c. The pylorus is indicated, not by a valve in the ordinary sense, but 

 by an ental, annular ridge consisting of a thickening of the muscular 

 coat and constituting- what is called a SPHINCTER. 



