author's abstract of this paper issued 

 bt the bibliographic service, jr.ne 2 



A CONTRIBUTION TO THE STUDY OF VASOMOTOR 



REFLEXES 



D. OGATA AND SWALE VINCENT 

 Physiological Laboratory, University of Manitoba, Winnipeg, Canada 



NINETEEN FIGURES 



CONTENTS 



1 . Introduction 355 



2. The influence of respiratory movements upon blood-pressures 357 



3. The effect of the strength of the stimulus upon vasomotor reflexes 331 



4. The influence of the frequency of stimulation upon vasomotor reflexes.:. 364 



5. The effects upon vasomotor reflexes of stimulating nerve trunks of dif- 



ferent categories (sensory, motor, and mixed nerves) and of different 

 sizes t 366 



6. Vasomotor reflexes from nerve terminations 370 



7. The influence of the ductless glands upon vasomotor reflexes 374 



8. The question as to which vascular areas are constricted or dilated on 



central stimulation of somatic nerves 375 



9. Summary 376 



I. INTRODUCTION 



General blood-pressure is affected reflexly by central stimula- 

 tion of various sensory nerves (reflex vasomotor action). This 

 subject has been studied already by a number of authors. A 

 complete list of the older investigations may be found in Tiger- 

 stedt's Lehrbuch der Physiologie des Kreislaufs,'*'^ papers by 

 Asher^ and Bayliss^ in Ergebnisse der Physiologie, and in Nagel's 

 Handbuch der Physiologie (Hofmann^O- The history up to 

 November, 1914, is given by Vincent and Cameron. ^^ As to 

 more recent important investigators of this problem, we may 

 refer to Porter,^^-^-' Martin, "-26 Ranson,35-36 Gruber,^'^ and their 

 respective co-workers, also to Domitrenko^ and Hunt.'^'^^ 



Even among these recent investigators there seems to be con- 

 siderable difference of opinion as to what may be regarded as 

 the usual or normal response to afferent impulses. Thus Porter 



355 



