68 INTESTINAL DIGESTIVE FLUIDS. 



ment is of course due to the pressure exerted conjointly by the straight 

 and circular fibres of the muscular coat. Anatomists divide the tube 

 into three portions the duodenum, jejunum, and ileum. 



Fig. 19. In Fig. 19 we have a pos- 



terior view of the duodenum, 

 a being its superior or pyloric 

 extremity, b the middle por- 

 tion, o the jejunum, d the gall- 

 bladder, i the cystic duct, p 

 hepatic duct, c the ductus com- 

 munis, m pancreatic duct. 



Soon after the chyme has 

 escaped through .the pyloric 

 valve into the duodenum, it 

 Posterior view of the duodenum. comes under the influence of 



the bile and pancreatic juices, which are sometimes discharged upon it 

 at a common point, and sometimes at a little distance apart. 



Digestive flu- r , . . 



ids of the in- Almost simultaneously it is submitted to the mechanical ac- 

 tion of the valvula? conniventes, which make their appearance 

 in the vertical portion of the duodenum, and continue in large numbers 

 until within the last two or three feet of the end of the tube. As the 

 intestine is distended, these project w4th a certain degree of turgidity, 

 and accomplish their mechanical object. 



But, besides the pancreatic and biliary fluids, there are other juices 

 thrown upon the passing chyme the enteric juice, which comes from 

 Brunner's glands, and a liquid oozing from the follicles of Lieberkuhn. 

 Moreover, the organisms known as Peyer's glands are affecting the con- 

 tents of the tube. Of each of these it is necessary therefore to speak. 



1st. The pancre'atic juice, secreted by the pancreas, an organ bearing a 

 Pancreatic resemblance in its anatomical construction to the salivary 

 tion e and n prop- gl an ^ s > an( * hence usually regarded as one of that group. 

 erties of. The juice itself is analogous to saliva, being viscid, and in its 



reaction alkaline: its specific gravity is about 1.008. Alcohol coagulates 

 it. It is said to contain no sulphocyanide nor any suspended particles. 

 It acts upon starch even more energetically than saliva, transmuting it 

 into sugar and lactic acid, and upon fats by forming them into an emul- 

 sion, so that they are readily absorbed. This has been found to take 

 place in artificial experiments by submitting fat substances to the juice 

 at a temperature of 100. 



Constitution of Pancreatic Juice of Dog. (From Schmidt.') 



Water 900.76 



Organic matter 90.38 



Inorganic " 8.86 



1000.00 



