A STUDY OF BLOOD MANUFACTURE 97 



10. THE PANCREAS 



Position, Form, Size. One of the most important of the 

 digestive glands is the pan'cre-as, which is situated just 

 below the stomach. In shape this organ may be compared 

 with that of a dog's tongue. It extends horizontally from 

 a curve of the small intestine near the pylorus to the spleen 

 at the left side of the body (Fig. 23). The pancreas is usu- 

 ally a little over six inches in length. 



Structure of the Pancreas. Like the salivary glands, the 

 pancreas is a racemose gland, consisting of gland recesses, 

 ductules, and a main duct. The latter extends through the 

 length of the pancreas, and after uniting with a duct from 

 the liver (Fig. 30, g), opens into the small intestine not far 

 from the pylorus. Within the gland recesses is secreted the 

 pancreatic juice, which is poured out through the duct just 

 described upon the food after it has entered the small intestine. 



Functions of the Pancreatic Juice. The pancreatic juice is 

 alkaline. The food mass, therefore, becomes alkaline soon 

 after it enters the intestine. Pancreatic juice digests three 

 of the nutrients, namely, starch, proteids, and fats. Indeed, 

 with the single exception of insoluble salts, our foods could 

 be digested by this one juice. Like saliva, pancreatic juice 

 changes starch into sugar, and like gastric juice, it converts 

 proteids into peptones. The pepsin of the gastric juice, 

 however, always requires the presence of an acid (hydro- 

 chloric), while the ferments of the pancreatic juice work 

 only in the presence of an alkali. 



Digestion of Fats. 1 The heat of the body melts much of 

 the fat before it reaches the intestine, but this liquid cannot 

 be absorbed until it has been digested more thoroughly. 

 Pancreatic juice digests fats in two ways : either by making 

 them into an e-mul'sion, or by converting them into soap and 

 glycerin. The latter process is called sa-pon-i-Ji-ca'tion (Latin 

 sapo = soap -\-facere = to make). These changes are shown 

 1 See "Laboratory Exercises," No. 22. 



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