THE SUPRARENAL CAPSULES OR ADRENAL BODIES. 349 



and from the phrenic and pneumogastric, and upon these there are 

 ganglia. 



Functions. Addison's disease is defined as u a disease 

 marked by a peculiar bronze-like pigmentation of the skin, early 

 and severe prostration, and progressive anemia, and usually ending 

 fatally. It is due to tubercular disease of the suprarenal cap- 

 sules." 



In 1855 Addison discovered the connection of the disease 

 above described with pathologic changes in the suprarenal bodies, 

 and removal of both of them experimentally by Brown-Se'quard 

 produced a similar condition, excepting the discoloration of the 

 skin, and a fatal result, usually within twelve hours. It was sur- 

 mised that the absence of pigmentation was due to the speedy 

 death. Since then the capsules have been crushed, with the effect 

 of producing the skin changes. Within recent years the suprarenal 

 capsules have been frequently removed, always w^ith a fatal result 

 within three days, and the blood of such animals when injected 

 into other animals whose capsules have been removed is toxic, 

 while if normal blood is injected into the veins of the latter their 

 life is prolonged. It is supposed from this that the function of 

 the suprarenal capsule is to destroy some toxic substance in the 

 blood ; this accumulates when these bodies are removed, and such 

 blood is poisonous. This is the autotoxication theory. 



Schafer has injected into animals watery and glycerin extracts 

 of the capsules, the results varying with the amount injected and 

 the animal experimented upon. In the cat and dog large doses 

 produce quickened and augmented heart-beat, shallow and rapid 

 respiration, and fall of temperature. Intravenous injection of 

 suprarenal extract produces, according to Schafer, a powerful 

 physiologic action upon the muscular system in general, greatly 

 prolonging the contraction of a muscle in response to a single ex- 

 citation of its nerve (Fig. 191), but especially upon the muscular 

 walls of the blood-vessels and heart. A certain amount of action 

 is also manifested upon some 'of the nerve-centers in the bulb, 

 especially in the cardio-inhibitory center, and to a less extent upon 

 the respiratory center. The blood-pressure is greatly increased, 

 due to contraction of the arterioles, the extract acting upon the 

 muscular coat of these vessels directly, and not through the vaso- 

 motor center. 



The active principle which produces these physiologic effects is 

 obtained from the medulla, and it has been demonstrated that so 

 small an amount as Too ^ OQO part of a gram per kilo of body- 

 weight, equivalent to 7-3^77-0 g ram f r an adult man, will produce 

 distinct physiologic results upon the heart and arteries ; but 

 whether it is the alkaloidal substance, epinephrin, isolated by Abel, 

 or the crystallizable one obtained by Takamineand called adrenalin, 

 has not yet been determined. 



Schafer draws the following conclusions : " It may be consid- 



