98 HUMAN BIOLOGY 



bring about the digestion of fats and complete the digestion 

 of starch and proteins. 



The pancreas (Fig. 26) lies just below the stomach and extends 

 from the region of the pylorus toward the left side of the body. 

 Within the gland is secreted the pancreatic juice, which is poured out 

 through a duct upon the food just after it enters the small intestine. 

 Pancreatic juice digests three of the nutrients; namely, starch, pro- 

 teins, and fats. Like saliva, pancreatic juice changes starch into 

 sugar, and like gastric juice, it converts proteins into peptones. 

 The heat of the body melts much of the fat before it reaches the in- 

 testine, but this liquid cannot be absorbed until it has been still 

 further acted upon chemically by the pancreatic juice and bile. 



VI. THE LARGE INTESTINE AND ITS FUNCTIONS 



136. Position, form, and size. The large intestine is the last 

 portion of the alimentary canal. It is a tube five or six feet long, 

 with a gradually decreasing diameter. Beginning in the lower right- 

 hand region of the abdominal cavity as a sac-like pouch (Fig. 26), 

 the large intestine passes upward on the right side of the body cavity 

 to the lower surface of the stomach ; it then crosses the abdominal 

 cavity ; a third portion continues downward on the left side. The 

 large intestine then takes an S-shaped course and passes to the ex- 

 terior of the body by a short, straight tube. 



137. Vermiform appendix. On the right side of the body, and 

 connected with the beginning of the large intestine, is a small, tubular 

 sac about the size of a lead pencil, and usually about four inches 

 long (Fig. 26). From its more or less twisted shape it has received 

 the name vermiform appendix (Latin, vermiform = worm-shaped). 

 Appendicitis is a diseased condition arising from inflammation in the 

 tissues of the appendix. 



VII. ABSORPTION FROM THE ALIMENTARY CANAL 



138. Necessity for the absorption of food. We have 

 now learned something of the processes of digestion. We 



