ABSORPTION OF FOOD 



L75 



the food, faeces (fe'sez), is of much importance in main- 

 taining health, because the bacteria living in the digestive 

 tract cause the waste material to decay and fche poisonous 

 substances thus formed are injurious when absorbed into 

 the blood. 



Foods normally remain in the stomach from one to five 

 hours, and in the small intestine about four hours; while 

 they may be from six to 

 twenty-four hours in 

 passing through the 

 large intestine. 



We become hungry 

 each day and feel re- 

 lieved only after eating. 

 A person frequently eats 

 a large meal because of 

 an extra amount of work 

 that is to follow. But 

 is he helped to do the 

 extra work ? Probably 

 not, for the strength to 

 do the work of to-day 



comes from the food eaten yesterday, or possibly the day 

 before yesterday. The food, even after digestion is com- 

 pleted, must pass through many changes before it is built 

 up into protoplasm. The actual building of the food into 

 protoplasm is the process for which the word nourishment 

 is used, and it should not be confused with absorption. 



Water. 



Figure 190. — Home-made Apparatus 

 to show Osmosis. 



Food as 

 purchased 

 contains 



Edible portion 



e.g., flesh of meat, yolk and 

 white of eggs, wheat, flour, etc 



Nutrients 



Protein. 



Fata 



( Sarbohydrafe 9. 



Mineral mat; 



Refuse 

 e.g., bones, entrails, shells, brain, etc. 



