Human physiology . ibitory effect. This harmoniseswith the conclusions of Bayliss and Starling, which may be brieflysummarised. According to these authors, no tonic influence on the intestines,such as is apparently exercised by the splanchnic, can be attributedto the vagus. Generally speaking, division of the vagi has no iv DIGESTION IN THE INTESTINE 251 perceptible effect, either immediately or remotely, upon the move-ments of the intestines. Peripheral stimulation of the vagi (after division of bothsplanchnics, as recommended by van Braam-Houckgeest andJacobi, so as to remove the tonic inhib
Human physiology . ibitory effect. This harmoniseswith the conclusions of Bayliss and Starling, which may be brieflysummarised. According to these authors, no tonic influence on the intestines,such as is apparently exercised by the splanchnic, can be attributedto the vagus. Generally speaking, division of the vagi has no iv DIGESTION IN THE INTESTINE 251 perceptible effect, either immediately or remotely, upon the move-ments of the intestines. Peripheral stimulation of the vagi (after division of bothsplanchnics, as recommended by van Braam-Houckgeest andJacobi, so as to remove the tonic inhibitory impulses passing alongthese nerves to the intestines) constantly produces temporarydiminution or cessation of the intestinal contractions, owing to thecardiac inhibition which causes intestinal anaemia. If the inhi-bition of cardiac activity is prevented by intravenous injection ofatropine, peripheral excitation of either vagus has no effect on theintestine. But if the stimulation is repeated several times an. FIG. ,sti.—Tracingiof intestinal rhythm as in Fig. So, during a later .stimulation of right vagus.(Bayliss and Starling.) In this tracing tin- primary inhibitory effect is scan/ply visiblr, whilethe subsequent motor effect is strongly marked, and at one point produces a tonic spasmwhich obliterates the intestine and compresses the balloon. augmentor effect sets in, which increases with each first effective stimulus is expressed in a temporary inhibitionwhich causes the dropping of one or two beats. In the succeed-ing stimulations there is a double effect, the primary inhibitionis followed by an augmented rhythm ; the beats increase inamplitude and frequency, and the relaxation is incomplete, so thatthere is a great increase of muscular tone (Fig. 85). In many casesthe excitation is so pronounced that the lumen of the gut andballoon are obliterated altogether by a strong tonic contraction(Fig. 86). There seems to be no relation between the exte
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