152 



GROWTH 



striking of all, an excessive heat production which often mani- 

 fests a definite hyperpyrexia. The whole picture is that of an 

 excessive drive of metabolism. The rate of oxidation, that is the 

 measure of metabolism, may be increased to 20, 50, or even 100 

 per cent above the normal. In the milder stages of hyperthy- 



Figure 77. The thyroid gland of man showing its form, size, 

 and location. After Spalteholz. Hand Atlas of Human 

 Anatomy. By permission of Verlag S. Hirzel, Leipzig. 



roidism such persons are often the aggressive, energetic business 

 men, the social reformers, and at times the unbalanced fanatics. 

 Physiologically they lead a more active life and at a faster pace. 

 They quickly run their course, generally to an extreme pa- 

 thology unless aided medically. 



Hyperthyroidism is due to an excessive production of an ac- 

 tive hormone. The hormone is discharged from the gland folli- 

 cles into the blood stream, through which it reaches all parts of 

 the body. Its amount depends not so much on the size of the 



