CHAPTER XVII 

 DISEASES DUE TO MALADJUSTMENT 



Disease May Be Defined in general terms as abnor- 

 mality in the functioning of living protoplasm; in other 

 words, as a condition of things in which metabolism is not 

 proceeding as it should. Metabolism (see Chap. VIII) 

 is an affair of the individual cells. The disturbance of 

 metabolism which constitutes disease is therefore, in the 

 last analysis, also an affair of individual cells. But, as 

 the previous chapters -in this section have tried to make 

 clear, the cells which make up the body do not function 

 independently; what one cell does may influence the ac- 

 tivity of cells even at great distances within the body. 

 It is evident, therefore, that maladjustment, or the fail- 

 ure of the various cells to interact properly, is a fruitful 

 cause of disease. For example, if the cells that make up 

 the heart muscle do not function properly the circula- 

 tion of blood is impaired and the cells throughout the body 

 will suffer, the exact degree depending on how far the 

 transportation system falls short of normal efficiency. 



The Maladjustments from which cells suffer are often 

 the immediate result of improper functioning of the 

 mechanisms for correlation. Thus we have a group of 

 diseases due to impaired hormone control, and another 

 group due to impaired nervous control. The maladjust- 

 ment may be nutritional, that is to say, the materials 

 necessary for metabolism may fail to be furnished 

 of proper sorts or in correct amounts. A third group 

 of maladjustments may result from mechanical in- 

 juries of one sort or another, although with regard to 

 these it should be noted that the immediate results of me- 

 chanical injury are not ordinarily classed as diseases. 



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