A text-book of physiology for medical students and physicians . Fig. —Sketch to show the accel-erator and augmentor) branches from thestellate ganglion (in the cat. left side): 1,the ventral branch of the annulus (ansasubclavia); 2, small branch not constantlypresent; 3, Boehms accelerator nerve(X. cardiacus e ganglio stellato). THE CARDIAC NERVES. 5S5 The Action of the Accelerator Fibers.—In experimentalwork the accelerators are usually stimulated in one or more of thebranches represented schematically as 5, 3, 6, in Fig. 243, or 3, inFig. 244, The effect is an increase in the rate of be
A text-book of physiology for medical students and physicians . Fig. —Sketch to show the accel-erator and augmentor) branches from thestellate ganglion (in the cat. left side): 1,the ventral branch of the annulus (ansasubclavia); 2, small branch not constantlypresent; 3, Boehms accelerator nerve(X. cardiacus e ganglio stellato). THE CARDIAC NERVES. 5S5 The Action of the Accelerator Fibers.—In experimentalwork the accelerators are usually stimulated in one or more of thebranches represented schematically as 5, 3, 6, in Fig. 243, or 3, inFig. 244, The effect is an increase in the rate of beat of the heart,which may be very evident, amounting to as much as 70 per cent,or more of the original rate, or may be very slight. When accelera-tion is obtained the latent period is considerable and the heartdoes not return at once to its normal rate upon cessation of thestimulus (see Figs. 245 and 246). In some cases the effect upon theheart is an acceleration pure and simple,—that is, the rate of beat is. Fig. 245.—To show the acceleration of the heart-rate in dog upon stimulation of theaccelerator fibers. The uppermost line gives the heart-rate as recorded by a Hiirthle manometerinserted into the carotid; the middle line indicates the beginning and duration of the stimulus(tetanizing induction shocks); the bottom line marks seconds. The pulse-rate was increasedfrom 105 to 135 per minute. The heart did not recover its normal rate until thirty secondsafter the stimulation. increased without any evidence of an increase in the force of thebeats. The larger number of beats is offset by the smaller amplitudeof each beat; so that the blood-pressure in the arteries is other cases the effect upon the heart may be an increase not onlyin rate but also in the force or amplitude of the beats, or the ratemay remain unaffected and only the amplitude of the heartbeats be increased. For these reasons most authors favor theview that the accelerator nerves, so called, co
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