Chap. XVII] 



URINARY SYSTEM 



325 



The waste matters 

 lungs, skin, liver, and 

 (1) By the urinary 

 organs : 



(2) By the lungs 



(3) By the skin : 



(4) By the liver : 



(5) By the intes- 

 tines : 



discharged relatively by the urinary organs, 



intestines may be stated as follows : — 



All, or nearly all, the urea and allied bodies.^ 

 These waste products result from the me- 

 tabolism of food proteins and body tissues. 



The greater portion of the salts. These 

 salts represent those taken into the body 

 and not utilized, also those that result 

 from the neutralization of acids and the 

 metabolism of foods and tissues. 



A large amount of water. This consists of 

 water taken as such with food, and that 

 formed in the body as the result of chem- 

 ical reactions. 



A very small quantity of carbon dioxide. 



The greater part of the carbon dioxide, 

 formed by oxidation. 



A considerable quantity of water. 



A small quantity of urea is eliminated in 

 diseased conditions of the kidneys. 



A variable but, on the whole, large quantity 

 of water. This is influenced by temper- 

 ature, and the amount excreted by the 

 kidneys. 



A small quantity of salts. 



A small quantity of urea. Under normal 

 conditions the quantity of urea is negli- 

 gible, but in diseased conditions of the 

 kidneys or when free perspiration is in- 

 duced, the quantity is increased. 



A small quantity of carbon dioxide.' 



A small quantity of bile. This contains 

 waste products that result from chemical 

 reactions that occur in the liver. 



Undigested and indigestible food material. 



A small quantity of salts. 



In diseased conditions of the kidneys, some 

 urea and allied bodies. 



* Uric acid, hippuric acid, creatin, creatinLa, xanthin, etc. 



