File:American journal of physiology (1898) (14782342505).jpg

Identifier: americanjourn01ameruoft (find matches)
Title: American journal of physiology
Year: 1898 (1890s)
Authors: American Physiological Society (1887- ) American Physiological Society (1887- ). Abstracts of papers presented at the fall meeting American Physiological Society (1887- ). Proceedings
Subjects: Physiology Physiology
Publisher: (Bethesda, Md., etc.) American Physiological Society (etc.)
Contributing Library: Gerstein - University of Toronto
Digitizing Sponsor: University of Toronto

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s stopped by a faradic current ^ See Hough: Journal of physiology, 1895, xviii. p. r6i.-5 i86 D. W, Harrington. of only moderate strength. For a short time after this I noticed thatin some guinea-pigs the heart was stopped by a moderately strongcurrent (the secondary coil being at about lO cm.), whereas in othersthe strongest current used (the secondary coil being at o cm.) wasunable to stop it. During the latter part of February and throughoutMarch and April the heart was invariably brought to a standstill byfaradic currents of the strength commonly used in physiological work,/. c, just perceptible when applied to the tongue. In some casesvery weak currents, such as are obtained when the secondary coilstands at 24, 28, and 30 centimetres from the primary, sufficed tocause stoppage. The curves of inhibition obtained during the first period differedin several respects from those obtained during the second period. Inthe former (see Fig. i) the slowing of the heart and the fall of blood-
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FiGURE I. Inhibition from stimulation of the left vagus, with the secondary coil at 5 cm.Time in seconds. The line of zero pressure is not shown. The writing-points of themanometer and of the stimulating key were in the same vertical line. pressure were gradual; the fall of pressure was not very great inproportion to the normal blood-pressure, which as a rule was consider-ably higher during the first than during the second period. Thereturn of the blood-pressure and the heart-rate to the normal, after thecessation of stimulation, was gradual and fairly regular, and inhibitionwas followed by comparatively little irregularity of heart-rate or ofblood-pressure. On the other hand, during the second period thestopping of the heart and the fall of blood-pressure were sudden, thedescent in the curve being sometimes almost vertical (see Fig. 2).The blood-pressure was very irregular after the cessation of stimula-tion, sometimes failing to return to the ordinary height, while morefrequently it

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