268 



DIGESTION. 



The observations which, were made on fats, melted butter, and cod-liver oil, showed 

 that the pure intestinal juice had little or no action upon them. These substances always 

 appeared in the fasces unchanged. When, however, fatter matters were taken into the 

 stomach, they were discharged from the upper opening in the intestine, in the form of a 

 very fine emulsion, and could not be recognized as fat. 



It is evident, from these facts, that the intestinal juice is important in digestion, more 

 as a fluid which aids the general process as it takes place in the small intestine than as 

 one which has a peculiar action upon any distinct class or classes of alimentary princi- 

 ples. It undoubtedly assists in completing the digestion of albuminoid substances and in 

 transforming starch into sugar. Although, in the latter process, its action is very 

 marked, the same property belongs to the saliva and the pancreatic juice. Intimately 

 mingled as it always is during digestion with the bile and the pancreatic juice as well 

 as with various alimentary substances, the intestinal juice should be studied as it operates 

 upon the food, in connection with the other fluids found in the small intestine, the diges- 

 tive action of all being most intimately associated. 



Pancreatic Juice. 



The physiological anatomy of the pancreas does not demand a very extended consid- 

 eration, as most of the points of its descriptive anatomy have no direct relation to its 

 physiology, and its minute anatomy belongs properly to the subject of secretion. The 

 pancreas is a glandular organ, situated transversely id the upper part of the abdominal 

 cavity, and closely applied to its posterior wall. Its form is elongated, with an enlarged, 

 thick portion, called the head (which is attached to the duodenum), a body, and a pointed 

 extremity, which is in close relation to the hilum of the spleen. Its average weight is 

 from four to five ounces ; its length is about seven inches ; its greatest breadth, about an 

 inch and a half; and its thickness, three-quarters of an inch. It lies behind the perito- 

 neum, which covers only its anterior surface. 



FIG. 73. G all-bladder, ductus choledochus, and pancreas. (Lc Bon.) 



a, gall-bladder; &, hepatic duct; c, opening of the second duct of the pancreas; d, opening of tho pancreatic and 

 the bile-duct; e, e, duodenum ; /, ductus choledochus; p, pancreas. 



According to Bernard, who has made numerous investigations into the anatomy of 

 this gland, there are nearly always, in the human subject, two ducts opening into the 

 duodenum ; one which opens in common with the ductus communis choledochus, and 

 one which opens about an inch above the main duct, called by Bernard the recurrent or 



