THE PANCREAS 



377 



to a pulpy mass, the chyme. This peptonized/00d contains most of the total 

 quantity of food eaten, little having been absorbed, as we shall see later, but 



FIG. 264. FIG. 265. 



FIG. 264. Piece of Small Intestine (previously distended and hardened by alcohol), 

 Laid open to Show the Normal Position of the Valvulae Conniventes. 



FIG. 265. Section of the Pancreas of a Dog During Digestion, a, Alveoli lined with 

 cells, the outer zone of which is well stained with hematoxylin; d, intermediary duct lined 

 with squamous epithelium. X 350. (Klein and Noble Smith.) 



much of the starch has been changed to soluble maltose and dextrose and 

 the protein to albumoses and peptones. The discharge from the stomach 

 through the pyloric valve to the duo- 

 denum has been going on through 

 three or four hours on an average for 

 each full meal. This stream of food 

 passing down the small intestine, 

 slowly because of the valvulse con- 

 niventes, meets a number of secretions 

 which contain enzymes which act on 

 each of the three great food principles, 

 proteins, fats, and carbohydrates. 

 These secretions are the pancreatic 

 fluid, the succus entericus, and the 

 bile. 



The Pancreas. The pancreas 

 is situated within the curve formed 

 by the duodenum, and its main duct 

 opens into that part of the small intes- 

 tine through a duct common to it and 



to the liver and about two and a half , 



FIG. 266. Section of the Pancreas of 



inches from the pylorus. Armadillo, Showing the Two Kinds of 



The pancreas bears some resem- Gland-structure. (V. D. Harris.) 



