238 



THE PANCREAS. 



by the dissolved soap, are quite sufficient to explain the per- 

 manency of emulsions of fat. 



Milk-curdling Enzyme, of the Pancreatic Juice. Milk, to which 

 an extract of the pancreas has been added, coagulates, and the 

 term pancreatic casein has been applied to this precipitate. It is 

 probably a substance intermediate between casein and caseinogen. 

 The coagulating agent is considered to be an enzyme, though 

 nothing definite is known about it. 



Innervation of the Pancreas. The nerves which supply 

 this organ are from the celiac plexus of the sympathetic, together 

 with some fibers from the right vagus, and are non-medullated 

 and gangliated. When food enters the stomach of a dog, almost 

 immediately the secretion of pancreatic juice begins, and is at 

 a maximum in from one to three hours. It then diminishes until 

 about five or six hours after the meal is taken, when it again 

 increases until the ninth or eleventh hour, and again diminishes 

 until the sixteenth or seventeenth hour, when it is practically nil. 

 Fig. 133 shows this in the dog. Just what the facts are in man 

 is unknown, although it is believed that the secretion begins about 

 the time of entrance of food into the stomach ; but its increase and 



FIG. 133. Curve of the secretion of pancreatic juice during digestion. The 

 figures along the abscissa represent hours after the beginning of digestion : the 

 figures along the ordinate represent the quantity of this secretion in cubic centi- 

 meters. Curves of two experiments are given (after Heideuhain). 



diminution would, doubtless, vary very materially from those of 

 the dog, which was fed but once during the day. 





