THE SECRETION OF THE PANCREATIC JUICE. 307 



perature of 40 C A strip of this paper about the length of a finger immersed 

 and fat 4 ^ ^ ^^ ^^ * L[d P * UQ f ^% U P n starfhes^umln 

 The pancreas of new-born infants contains no diastatic ferment, but both 

 peptic and fat-splitting ferments. Diseases of infants, diarrhea at times appear 

 , h V h-t a Tt +1 6Ct V he aCtivity f the P ancre *s- Slight diastatic p P ower 

 of the fir^ ear ^ m f Ufe> com P lete ac tivity only after the lapse 



The milk-curdling activity depends on the presence of a ferment 

 according to W. Kuhne and W. Roberts, which can be extracted by 

 means of a concentrated solution of sodium chlorid. 



The pancreas also prepares a sugar-splitting ferment. If a solution 

 of sugar is digested with an aqueous or glycerin extract of pancreas, 

 the amount of sugar diminishes. 



THE SECRETION OF THE PANCREATIC JUICE. 



In the case of the pancreas, a resting stage, in which the gland is flabby 

 and pale yellow, and a stage of secretory activity, in which the organ 

 appears swollen and pale red, can be distinguished. The latter occurs 

 only after the ingestion of food, and results probably in consequence of 

 reflex excitation through the nerves of the alimentary canal, and ap- 

 parently in consequence of the moistening of the intestinal mucous mem- 

 brane with the acid gastric contents, for acids are the most powerful 

 excitants of this secretion. W. Kiihne and Lea found that all the lobules 

 did not take part in the secretory activity at the same time. The pan- 

 creas in herbivora secretes continuously. * 



According to Bernstein and Heidenhain, the secretion begins to flow 

 with the entrance of the food into the stomach, the quantity reaching 

 its maximum in the second or third hour. After this the amount de- 

 creases between the fifth and the seventh hour; then, in consequence 

 of the passage of all of the dissolved matters into the duodenum, it rises 

 again between the ninth and the eleventh hour, and finally falls gradually 

 between the seventeenth and the twenty-fourth hour, to the point 

 of complete cessation. 



^ During the act of secretion the blood-vessels behave like those of the 

 salivary gland after stimulation of the facial nerve; they are dilated, the 

 venous blood being bright red. It is, therefore, probable that a similar 

 nervous mechanism is active here. In general, the activity of the gland 

 is in large measure dependent upon an adequate blood-supply; anemic 

 conditions impair the secretory processes. The secretion, in the rabbit, 

 is under a secretory pressure of over 17 mm. of mercury. 



The nerves are derived from the hepatic, splenic and superior mesenteric 

 plexuses, to which the pneumogastric and splanchnic nerves send branches. The 

 secretion of the gland is excited by stimulation of the medulla oblongata, of the 

 splanchnic nerves (feebly), of the peripheral stump of the pneumogastric nerve, 

 in consequence of which the amount of ferment in the juice is increased, as well 

 as of the gland itself by means of induction-currents. Reflex increase in the 

 secretion is brought about by stimulation of the central stump of the lingual nerve, 

 at times also by that of the central stump of the pneumogastric nerve. The 

 secretion is suppressed by atropin, by excitation through the act of vomiting, as 

 well as by stimulation of the pneumogastric nerve or its central stump, as well as 

 of other sensory nerves, as, for example, the crural and sciatic nerves. Destruction 

 of the accessible nerves of the pancreas surrounding the blood-vessels renders the 

 stimulation mentioned ineffective. On the other hand the secretion of a watery, 

 paralytic, slightly active secretion becomes permanent; and the amount is then 

 no longer modified by the ingestion of food. 



