CHAPTER XVII. 



URINE: GENERAL CHARACTERISTICS OF NOR- 

 MAL AND PATHOLOGICAL URINE. 



Volume. The volume of urine excreted by normal individuals 

 during any definite period, fluctuates within very wide limits. The 

 average output for twenty-four hours is placed by German writers 

 between 1,500 and 2,000 c.c. This value is not strictly applicable 

 to conditions in America however since it has been found that the 

 average normal excretion of the adult male American falls within 

 the lower values of 1,000-1,200 c.c. The volume-excretion is in- 

 fluenced greatly by the diet, particularly by the ingestion of fluids. 



Certain pathological conditions cause the output of urine for any 

 definite period to depart very decidedly from the normal output. 

 Among the pathological conditions in which the volume of urine 

 is increased above normal are the following: Diabetes mellitus, 

 diabetes insipidus, certain diseases of the nervous system, con- 

 tracted kidney, amyloid degeneration of the kidney and in convales- 

 cence from acute diseases, in general. Many drugs such as calomel, 

 digitalis, acetates and salicylates also increase the volume of the 

 urine excreted. A decrease from the normal is observed in the 

 following pathological conditions : Acute nephritis, diseases of the 

 heart and lungs, fevers, diarrhoea and vomiting. 



Color. Normal urine ordinarily possesses a yellow tint, the 

 depth of the color being dependent in part upon the density of the 

 fluid. The color of normal urine is due principally to a pigment 

 called urochrome: traces of hczmatoporphyrin, urobilin and uroery- 

 thrin, have also been detected. Under pathological conditions the 

 urine is subject to pronounced variations in color and may contain 

 many varieties of pigments. Under v such circumstances the urine 

 may vary in color from an extremely light yellow to a very dark 

 brown or black. Vogel has constructed a color chart which is of 

 some value for purposes of comparison. The nature and origin 

 of the chief variations in the urinary color are set forth in tabular 

 form by Halliburton as follows : 



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