THE SUPRARENAL CAPSULES OR ADRENALS 



489 



as 1856 that removal of the suprarenals is followed by the death of the 

 animal, but his experiments were repeated by others unfortunately on 

 less susceptible animals. These men 

 did not obtain the same results; and 

 it was concluded that the suprarenal 

 capsules had no function, or at least 

 that their function was not known. l 

 Death was preceded in the case of 

 Brown-Sequard's animals by symptoms 

 somewhat analogous to those of the b 

 disease of man known as Addison's 

 disease. The failures to reproduce these 

 symptoms have probably resulted from 

 incomplete removal or the presence of 

 accessory bodies. Accessory suprarenal- 

 like tissues, chromofile tissues, are com- 

 monly present in animals. Further, 

 if one gland is removed, the other 

 hypertrophies. The experiments of all 

 recent observers confirm the original 

 experiments of Brown-Sequard and show c 

 that the removal of the suprarenal cap- 

 sules is fatal. 



Oliver and Schafer found that injec- 

 tions of suprarenal extract produced 

 marked effects upon the muscular layer 

 of the arteries, the muscular tissue of 

 the heart, and the skeletal muscles. 

 The muscular layer of the arteries is 

 markedly contracted, causing a rise of 

 blood-pressure. 



The contractions of the heart with 



its nerves intact are small although they 



j T_ .LI t j i* FIG. 315. Vertical Section of 



are increased both in force and ampli- AdrenaL */, Capsule; B, cortex; C, 



tude. If the vagi are sectioned, the medulla; a, glomerular zone; b, fasci- 

 i j T j , v cular zone; c, reticular zone; v, vein 



slowing does not occur. Instead, the in medulla ; ' (Merk ei-Henle.) 



heart rate is accelerated through the 



accelerator nerves, the movements of the alimentary canal are de- 

 creased, the splanchnic vascular region is sharply constricted, the 

 urogenital musculature is stimulated to contraction, and the pupils are 

 dilated. In fact, Elliot and others after him have shown that all those 

 structures which are stimulated or inhibited by the action of sympathetic 

 mechanisms are stimulated by the active principle of this gland and in 



