Human physiology . tines; but after15 to 30 minutes they gradually become more active, the previouslymotionless intestine begins to beat rhythmically, and any con-tractions which were previously present become stronger and moreregular. The vessels become hyperaemic from vascular dilatation 250 PHYSIOLOGY CHAP. mving to paralysis of the vaso-constrictor fibres. Under normalconditions, therefore, the splanchnics have a restraining influenceon the intestinal movements, which ceases after section of thesenerves. This conclusion is strengthened by the result of stimulatingthe peripheral end of the
Human physiology . tines; but after15 to 30 minutes they gradually become more active, the previouslymotionless intestine begins to beat rhythmically, and any con-tractions which were previously present become stronger and moreregular. The vessels become hyperaemic from vascular dilatation 250 PHYSIOLOGY CHAP. mving to paralysis of the vaso-constrictor fibres. Under normalconditions, therefore, the splanchnics have a restraining influenceon the intestinal movements, which ceases after section of thesenerves. This conclusion is strengthened by the result of stimulatingthe peripheral end of the cut splanchnic immediately below thediaphragm, after inserting a small exploring balloon into a loop ofintestine. As shown by Fig. 84, after a somewhat prolonged latentperiod, there is a complete cessation of the rhythmic movementswith marked relaxation of the intestinal wall. When stimulationceases, there is a long after-effect, followed by gradual return ofthe rhythmical movements, and increased tone of the Fi<;. 85.—Intestinal contractions. Balloon method. (Bayliss and Starling.) Stimulation of rightvagus in neck of dog, after atropin. /, inhibition ; CF, carotid pressure; E, length ofexcitation. The influence of the vagus nerves on the movements of theintestines has also been the subject of not a little controversy. , Budge, Ludwig and Kupfer, Engelmann with many others,maintained that they have a motor action, and, notwithstanding-some differences of detail, it might be concluded from their resultsthat this was the exclusive effect. Bunch, however, observed incertain rare cases out of a large number of experiments, that thestimulation of the vagus may, like that of the splanchnic, produceinhibition. Ott (1904), again, expressly declared that peripheralstimulation of the vagi has an inhibitory effect. This harmoniseswith the conclusions of Bayliss and Starling, which may be brieflysummarised. According to these authors, no tonic influence on the intestine
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