336 ANATOMY FOR NURSES [Chap. XVII 



urates is decreased, and it accumulates in the blood and is deposited 

 in the tissues. 



Creatinin. — Creatinin represents a meat extractive and may be 

 taken into the body in food, or formed in the body by the oxida- 

 tion of certain proteins. 



Hippuric acid. — This is increased in amount by a vegetable 

 diet, so that it is thought to represent a waste product that results 

 from the metabolism of vegetables. However, some hippuric 

 acid is excreted even on a meat diet, so that it may result from the 

 metabolism of proteins, or it may be derived from the jjrocess of 

 protein putrefaction that occurs in the intestines. 



Salts. — The salts found in the blood are derived partly from the 

 food eaten, and partly from the metabolism of proteins, particu- 

 larly the neutralization of acids. Sodium chloride is the most 

 abundant, and, next to urea, is the chief solid found in urine. In 

 certain inflammatory conditions, coupled with serous exudate, 

 the amount of sodium chloride excreted is very much diminished. 



Abnormal constituents. — The chief abnormal constituents 

 that are liable to appear in the urine are albumin, glucose, indican, 

 acetone, casts, calculi, pus, and blood. 



Albumin. — Normally the kidney cells do not allow albumin to 

 pass into the tubules, but a condition of temporary albuminuria 

 may follow overeating or severe muscular exercise. In abnormal 

 conditions of the kidneys associated with nephritis and acute 

 fevers, albumin is usually found in the urine. In cases of heart 

 disease, where the blood vessels of the kidney are subjected to ab- 

 normal pressure changes, albumin is usually present in the urine. 



Glucose. — In health the amount of glucose present in the blood 

 varies from 0.1 to 0.15 per cent. A higher per cent is irritating 

 to the tissues, so when the quantity of sugar eaten is greater than 

 the system can promptly change to glycogen and fat, the kidneys 

 secrete and excrete it. When glucose is found in the urine from this 

 cause, it is called temporary glycosuria. Temporary glycosuria 

 frequently follows an injury to the head, or occurs during convales- 

 cence from fevers. In these cases it is thought to be due to tem- 

 porary inability of the system to oxidize sugar. In the disease 

 called diabetes mellitus glucose persists in the urine. In mild 

 cases this condition can be controlled by lessening the amount 

 of carbohydrate food, but in severe cases glucose will appear in the 



