THE PANCREATIC SECEETION. 159 



with bile, secreted since the last meal; the acid chyme 

 stimulating the duodenal mucous membrane causes, 

 through the nervous system, a contraction of the muscular 

 coat of the gall-bladder, and so a gush of bile is poured out 

 on the chyme. From this time on both liver and pancreas 

 continue secreting actively for some hours, and pour their 

 products into the intestine. The glands of Brunner and 

 the crypts of Lieberkiilm are also set at work. All of these 

 secretions are alkaline, and they suffice very soon to more 

 than neutralize the acidity of the gastric juice, and so to 

 convert the acid cliyme into alkaline chyle, which, as found 

 in the intestine after an ordinary meal, con tains a great va- 

 riety of things: water, partly swallowed and partly derived 

 from the salivary and other secretions; some undigested 

 proteids; some unchanged starch; oils from the fats eaten: 

 peptones formed in the stomach but not yet absorbed; sal- 

 ines and sugar, which have also escaped complete absorp- 

 tion in the stomach; indigestible substances taken with the 

 food; all mixed with the secretions of the alimentary canal. 

 The Pancreatic Secretion is clear, watery, alkaline, and 

 much like saliva in appearance. The Germans call the 

 pancreas the "abdominal salivary gland." In digestive 

 properties, however, the pancreatic secretion is far more 

 important than the saliva, acting not only on starch but 

 on proteids and fats. On starch it acts like the saliva, but 

 more energetically. It produces changes in proteids simi- 

 lar to those effected in the stomach, but by the agency of a 



How is an outpouring of bile on the chyme brought about ? Do 

 liver and pancreas cease secreting when the chyme enters the intes- 

 tine? What other glands are set to work? How is the acidity of 

 the chyme overcome? What is chyle? What does it usually con- 

 tain? 



Describe the pancreatic secretion. What foodstuffs does it net 

 upon? Describe its action on starch. How does it change proteids? 



