PANCREATIC JUICE. 



269 



accessory duct. The main duct is about an eighth of an inch in diameter and extends 

 along the body of the gland, becoming larger as it approaches the opening. The sec- 

 ond duct is smaller and becomes diminished in caliber as it nears the duodenum. Many 

 anatomists describe but a single duct, regarding the other as anomalous. The dissections 

 of Bernard, however, were very numerous and show the almost constant occurrence of 

 two ducts. 



In general appearance and minute structure, the pancreas is like the parotid and sub- 

 maxillary glands. By the older anatomists it was known as the u abdominal salivary 

 gland," on account of this resemblance in structure and an 

 assumed similarity in the nature of their secretions. Eecent 

 developments in the physiology of the pancreatic juice have 

 caused this name to be discarded. 



Bernard was the first to obtain normal pancreatic juice 

 from a living animal and to give a definite idea of its properties 

 and functions ; a point which it is proper to particularly insist 

 upon, inasmuch as, since his discovery, some have pretended 

 that the facts which he established had been demonstrated 

 before. The following method for collecting the pancreatic 

 juice from a living animal, one which we have repeatedly em- 

 ployed with success, is essentially that recommended by Ber- 

 nard: 



The animal generally employed by Bernard in these ex- 

 periments is the dog. Selecting one of tolerably large size, 

 he is secured to the operating-table and placed upon his left 

 side. An incision from three to four inches in length is then 

 made in the right hypochondrium, just below and parallel 

 with the border of the last rib. The parts are first divided 

 down to the fascia transversalis and the peritoneum. An 

 opening is then made into the abdominal cavity about half 

 the length of the incision through the skin and muscles, 

 which brings to view the duodenum and a portion of the pan- 

 creas. The duodenum, with the pancreas attached to it, is 

 then carefully drawn out of the abdomen. The next step is 

 to introduce a small canula into the principal pancreatic duct. 

 In the dog, there are always two pancreatic ducts ; a small 

 duct, which opens into the intestine at or near the opening of 

 the bile-duct, and a principal duct, which is situated about an 

 inch below. To collect the juice, the tube should be intro- 

 duced into the principal duct. This is found by turning the 

 duodenum and pancreas so as to expose the posterior surface 

 of the gland, when the duct, which is very short and almost 

 concealed by the tissue of the pancreas, may be seen oblique- 

 ly penetrating the intestinal wall. In the dog, the pancreas 

 is composed of two portions ; one, called the horizontal por- 

 tion, which is attached to the duodenum, and a vertical por- 

 tion, which passes away from the intestine between the folds 

 of the mesentery. The duct is generally situated near the 

 point where the pancreas ceases to be attached to the intes- 

 tine. The tissue of the pancreas is to be carefully pushed 

 away from the duct with the end of the canula or the point 

 of a knife, a small longitudinal slit is made in it with the 

 scissors, and a silver canula, about one-twelfth of an inch in diameter and four inches in 

 length, is introduced and firmly secured in place by a ligature wJiich has previously been 



FIG. 74. Canula for a pancre- 

 atic fistula. (Bernard.) 



A, stylet, the extremity of which 

 should pass a little beyond 

 the end of the canula J5. to 

 facilitate its introduction into 

 the pancreatic duct ; B, ean- 

 nla, provided with little 

 grooves c, c, to hold the 

 threads for Attachment into 

 the duct and into the bladder 

 used to collect the pancreatic 

 juice. 



