ABSORPTION AND ASSIMILATION 95 



and the opportunity should be given daily at a regular 

 time. Even if little food is eaten, the waste matters are 

 still formed, and need expulsion. It should be remem- 

 bered that it requires two days for food to pass the length 

 of the intestine, so refraining from food only a single day 

 does not make the intestine empty. 



When the intestine expels its contents too freely, there 

 is usually some irritating food which it is trying to expel. 

 So a dose of medicine, which will aid in its expulsion, is 

 required rather than something which will restrain the 

 action. 



135. Proper food. The stomach may be able to begin digesting 

 an improper meal, while the intestine is unable to finish the work. 

 Owing to the slowness with which the intestine acts, several meals 

 may be eaten before its failure becomes noticeable. Then the last 

 meal is blamed, instead of the offending meal. So persons may gain 

 wrong ideas about the digestibility of various articles of food. 



136. Headaches. A headache is generally due to disturbances 

 in digestion. Usually when the liver is stimulated by a proper medi- 

 cine, the headache ceases. Even if the headache is due to overwork, 

 probably it would not have come on if the digestive organs had been 

 performing their work properly. 



SUMMARY 



1. The peptone and glucose are taken up by the epithelial 



cells of the villi, and passed on to the blood in the 

 capillaries inside the villi. 



2. Emulsified fat is taken up by the epithelial cells of the 



villi, and passed on to the lacteals within the villi. 

 From there it goes to the thoracic duct, and finally 

 is poured into the large vein at the root of the 

 neck. 



3. About two gallons of fluid enter and leave the alimen- 



tary canal each day. 



