12 THE PHYSIOLOGY OF THE ADRENALS. 



led by unquestionable experiments to conclude that the su- 

 prarenal extract stimulated the vagus center, thus inhibiting 

 the heart. 



A second set of divergent views refers to the nervous 

 structures involved when the heart is separated from its in- 

 hibitory center by section of the vagus. The influence of the 

 extract, in this connection, is ascribed by Mankowsky 40 to 

 stimulation of the cardiac and respiratory centers; by Gott- 

 lieb, 41 to the direct stimulating effects of the substance upon 

 the intrinsic cardiac ganglia; by de Cyon, 42 to some action upon 

 the vasoconstrictor nerves and simultaneously upon the central 

 and peripheral ends of the cardiac accelerators; by Velich, 43 

 to stimulation of the vasoconstrictors; and finally by other 

 observers to various more or less complicated combinations 

 which all include some part of the nervous system as the seat 

 of primary effect. By inference, therefore, we are led to look 

 upon this system as the one upon which the specific principle 

 of the adrenals acts physiologically. 



The first question, which embodies the divergent views of 

 Cybulski, on the one side, and Oliver and Schafer, on the other, 

 resolves itself into this: Does the suprarenal active principle 

 act at all upon the inhibitory centers? 



It may prove useful in this connection to recall that, ac- 

 cording to prevailing doctrines, the functions of the heart are 

 governed by two sets of nerve-fibers. The one set, derived from 

 the splanchnic, increases the vigor of the heart-beat and tends 

 to quicken the number of beats in a given time. The other 

 set, which arises from the vagus, inhibits the vigor of the 

 heart-beats and their rate or rhythm. Both these "augmentor" 

 and "inhibitor" fibers receive their impulses from the medulla 

 oblongata and from a limited area of the upper portion of the 

 cord, and represent the external, or extrinsic, motor-supply of 

 the organ. Again, the medulla and the spinal area referred to 

 receive impulses including reflex impulses from all parts of 

 the organism, including the heart proper, and there is thus 



40 Mankowsky: Russian Archives of Pathology, Clinical Med., and Bact., vol. 

 v, No. 3, March, 1898. 



Gottlieb: Archiv fur exp. Path., Bd. xxxviii, 1896. 



*2De Cyon: Pfliiger's Archiv fur Physiol., vol. Ixii, p. 370, 1898. 



"Velich: Wiener med. Blatter, Nov. 11, 1897. 



