THE PANCREAS 373 



PROBLEM V. WHAT WORK IS DONE BY THE PANCREAS? 



Demonstration 4. What is the action of pancreatic juice on starch? 



Add some artificial pancreatic juice (made by mixing 5 grains of 

 pancreatin and 10 grains of baking soda in 100 c.c. of water) to some 

 dilute starch paste. Keep it at about body temperature for a few 

 hours, then test with Fehling's solution. What occurred when Feh- 

 ling's solution was added? What was the action of pancreatic juice 

 on starch? 



Demonstration 5. What is the effect of pancreatic juice on protein ? 



Using artificial pancreatic juice instead of a mixture of hydrochloric 

 acid and pepsin, carry out an experiment as described for the test for 

 the third tube in the Demonstration on page 369. Was any of the 

 white of egg digested? 



Demonstration 6. What is the effect of pancreatic juice on oils and 

 fats? 



Shake up oil and water. What happens? Then add a little alka- 

 line substance, e.g., baking soda. What happens? Xow shake up 

 water with artificial pancreatic juice. What happens? What is the 

 effect of pancreatic fluid on oils? 



Make a table to show the effect of pancreatic juice on nutrients. 



Position and structure of the pancreas. The partly digested 

 food in the small intestine comes in contact almost simultaneously 

 with secretions from the liver, the pancreas, and the intestinal 

 glands. We shall first consider the function of the pancreas. 

 The pancreas is one of the most important digestive glands in the 

 human body. It is a rather diffuse structure, resembling the 

 salivary glands. Its duct (joined with the bile duct from the 

 liver) empties into the small intestine a short distance below 

 the pylorus. 



Work done by the pancreas. Starch paste added to artificial 

 pancreatic fluid and kept at blood heat is soon changed to sugar. 

 Proteins, under the same conditions, are broken down into the 

 amino acids. Fats, which so far have been unchanged except to 

 be melted by the heat of the body, are changed by the action of 

 the pancreatic fluid and the bile into substances which can pass 

 through the walls of the food tube. If we test pancreatic fluid, 

 we find it strongly alkaline in its reaction. If two test tubes, one 

 containing olive oil and water, the other olive oil and a weak 

 solution of caustic soda (w T hich has an alkaline reaction), are 

 shaken violently and then allowed to stand, the oil and water will 

 quickly separate, while the oil and solution of caustic soda will 



