A text-book of physiology, for medical students and physicians . espiratory movements at a more rapidrate. Experiment lias shown that this influence consists in thetonic action of sensory fibers contained in the vagus and distributedto the lungs. It is flu; constant, effect, of these fibers on the respira-tory center which maintains the normal rhythm; when they aresevered the center drops into a slower, unregulated rhythm. Ex-periment, has shown, also, that when the central stump of thedivided vagus is stimulated artificially the respiratory center isaffected, as indicated by the respiratory m
A text-book of physiology, for medical students and physicians . espiratory movements at a more rapidrate. Experiment lias shown that this influence consists in thetonic action of sensory fibers contained in the vagus and distributedto the lungs. It is flu; constant, effect, of these fibers on the respira-tory center which maintains the normal rhythm; when they aresevered the center drops into a slower, unregulated rhythm. Ex-periment, has shown, also, that when the central stump of thedivided vagus is stimulated artificially the respiratory center isaffected, as indicated by the respiratory movements, in a varietyof ways which depend upon the strength of the stimulus and the INNERVATION OF THE RESPIRATORY MOVEMENTS. 667 condition of the center. The two results which are most constantlyobtained and which may therefore be especially emphasized are asfollows: first, with weak stimuli the inspiratory movements are in-hibited partially or completely, giving either smaller movements or,in a condition of narcosis, complete cessation of respirations, with. Fig. 269.—To show the effect of section of the vagi on the respiratory movements(rabbit). The right vagus was cut at x and caused a slight augmentation and slowingof the movements. The left vagus was cut at xx and caused first a short inhibition (dueto mechanical stimulation) which was then followed by the typical slow and deep respi-rations seen under these conditions.—{Dawson.) the thorax in the stage of passive expiration (Fig. 268), or, second,the rate of the inspiratory movements may be increased and thismay end finally in an inspiratory standstill,—that is, the respiratorymovements cease with the chest in an inspiratory position (Fig. 270),
Size: 2198px × 1137px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookautho, bookcentury1900, bookdecade1900, booksubjectphysiology
