148 THE INTERNAL SECRETIONS 1920 



It is believed to be, at first, functional and caused by 

 hypertonus of the arterial musculature, but later on 

 it assumes a partly organic character, the result of 

 changes in the arterial walls. Barker believes that the 

 different types of chronic arterial hypertension prob- 

 ably represent different stages in the development of 

 the same fundamental process which may advance with 

 variable rapidity and with variable associated involve- 

 ment of cardiovascular, renal, cerebral, and other 

 structures in different cases. This author then goes on 

 to call attention to the general changes which are 

 fundamentally responsible for the condition of high 

 blood pressure, and he states that in order to prevent 

 the development of this pathologic process underlying 

 high blood pressure "one should first get himself well- 

 born without constitutional inferiorities" and then 

 should avoid intoxications and infections and live a 

 well-balanced life, so ordering his activities that he can 

 satisfy his physical, economic, social, educational, 

 esthetic, and ethical desires in a well-balanced manner. 



For many years it has been considered fundamental 

 that toxemias favored high blood pressure and that 

 they did so first by causing an overactivity of the cir- 

 culatory system resulting in changes in the heart and 

 blood-vessels. Also that the toxemia irritated the 

 actual glomerular tissue of the kidneys and, there- 

 fore, made changes which tended toward what the 

 French have called "renal impermeability." Later our 

 ideas have veered a little, and it is now considered pos- 

 sible and probable that irritation of the blood-pressure- 

 raising mechanism of the adrenal glands, by means of 

 the poisons produced in the alimentary canal and else- 

 where, results in an increased activity of this pressor 

 mechanism and in this manner produces a functional 

 high blood pressure. 



Be this as it may, there is no doubt that high blood 

 pressure is merely a single manifestation of a serious 



