Physiology and biochemistry in modern medicine . B. Fig. 71.—Tracings showing the effects on the heartbeat of the frog resulting from stimulation ofthe sympathetic nerves prior to their union with the vagus nerve. (From Brodie.) and sympathetic are stimulated at the same time, as by exciting the vago-sympathetic in the frog, the first effect observed is that of the vagususually followed, after removal of the stimulus, by the sympathetic ef-fect. If the stimulus is maintained for a long time, so that the vagusbecomes fatigued, escapement will occur earlier than with pure vagusstimulation, and a
Physiology and biochemistry in modern medicine . B. Fig. 71.—Tracings showing the effects on the heartbeat of the frog resulting from stimulation ofthe sympathetic nerves prior to their union with the vagus nerve. (From Brodie.) and sympathetic are stimulated at the same time, as by exciting the vago-sympathetic in the frog, the first effect observed is that of the vagususually followed, after removal of the stimulus, by the sympathetic ef-fect. If the stimulus is maintained for a long time, so that the vagusbecomes fatigued, escapement will occur earlier than with pure vagusstimulation, and augmentation may become apparent. The sympatheticinfluence is, however, never so strong as that of the vagus. The twonerves are therefore not antagonistic in the sense that the one neutralizesthe effect of the other; but when both are stimulated, the heart respondsfirst to the vagus and later to the sympathetic. CHAPTER XXVITHE CONTROL OF THE CIRCULATION (Contd) THE NERVE CONTROL OF THE PERIPHERAL RESISTANCE As already explained, the nerve con
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