66 PHYSIOLOGY FOR NURSES 



bodies, seeds, grains of corn, ligaments; undigested 

 fragments of digestible food; some results of intestinal 

 secretion; inorganic salts, mucus, pigment, the results 

 of putrefaction, etc. 



End Results Summary 



The processes of digestion are merely preparatory: 

 the food is reduced by these processes to such a form 

 that it may be absorbed. Changes fully as important 

 take place after the food has left the alimentary canal, 

 constituting what is known as "metabolism." Unfor- 

 tunately, our knowledge regarding these changes is still 

 very poor, but it is to be hoped that much more will be 

 learned about them in the near future and more light 

 shed on the etiology (science of cause of disease) of the 

 diseases which are the result of "metabolic disturb- 

 ances." 



When starch has been digested; that is, has been re- 

 duced by the action of ptyalin, amylase, and maltase to 

 the absorbable dextrose, it enters the capillaries of the 

 intestinal villi and is carried in the portal circulation 

 to the liver. Normally, AVC have 1 to 2 per cent of dex- 

 trose in our blood, but it is evident that after a meal 

 containing much starch or sugar, the amount in the 

 portal vein must be much more than this. Should this 

 sugar-laden blood escape into the general circulation 

 and eventually pass through the kidneys, these organs 

 would not be able to retain the sugar in the blood, and 

 it would be passed out in the urine, giving rise to a 

 " glycosuria. " The liver, however, has the power of 

 fixing this dextrose in a form in which it may be stored ; 

 changing it into the glycogen or animal starch which 

 has already been mentioned. Therefore, after a meal 

 containing carbohydrate, this compound can be easily 



