THE ORGANIZATION OF THE INDIVIDUAL 



25 



4. The respiratory system, which has for its function the providing of 

 an adequate gaseous exchange between the blood and the outside air. 



5. The excretory system, which has as its function the elimination of 

 an important part of the wastes that are invariably produced by 

 the living process. Structurally related to item 9 below and some- 

 times lumped with it as the urinogenital system. 



breathihg 

 ingestion 



external respiration 

 circulation 



digestion 

 excretion 



absorption 



elimination 



assimilation 

 oxidation 

 secretion 

 excretion 



small intestine 

 kidney 



arge intestine 



urinary bladder 



Fig. 2.5. Division of labor as illustrated by some of the structures and processes of the 

 human body. (Based on a figure in Wolcott, Animal Biology.) 



