MOVEMENTS OF THE STOMACH. 139 



ganglion galvanized. After a few seconds, active movements of the small 

 intestines takes place. The cord connecting the inferior cervical with the 

 first thoracic ganglion is now divided, and the lower extremity galvanized. 

 The intestines remain quiescent. But if the upper extremity be galvanized, 

 active intestinal movements again occur. 1 The Pneumogastrics are believed 

 by many to be also a channel by which impulses proceeding from the cerebro- 

 spinal centres are transmitted to the intestines, since electrical excitation of 

 these nerves usually, though not always, produces contractions which com- 

 mence in the stomach, and are most evident when the splauchnics have been 

 divided. 1 ' and also at a short interval after death. It must be admitted how- 

 ever that the effects of stimulating the pneumogastrics are very inconstant. 3 

 96. The Splanchnic nerves are now well known to be the vaso-motor nerves 

 of the abdominal viscera, and it is difficult to say whether when irritated, they 

 act directly upon the muscular fibres or nervous ganglia of the intestines, or 

 whether their influence is exerted indirectly by modifying the size of the 

 vessels, and the quantity of blood supplied to these parts. According to 

 some experimenters, 4 when irritated by the application of exceedingly feeble 

 currents of electricity, the splanchnics act like ordinary motor nerves, and 

 produce contraction of the muscular coats. If, however, the current be of 

 moderate strength, so far from causing con traction, these nerves are declared by 

 Pfliiger, to restrain or inhibit the peristaltic movements, and many excellent 

 observers corroborate his statements. 3 On the other hand there seems to be 

 little doubt that shortly after death, irritation of the splauchnics will produce 

 peristaltic movements. To explain these phenomena, Nasse has suggested 

 that the splauchuics may contain both motor and inhibitory fibres, the former 

 being more irritable than the latter ; that is to say, responding to a feebler 

 stimulus, and at the same time retaining their irritability for a longer period 

 after death. Nasse, experimenting on rabbits, found that the inhibitory effect 

 of irritating the splauchnics immediately after death, was limited to the small 

 intestines; the movements of the stomach, colon, and rectum remaining un- 

 affected. The arrest of movement took place so quickly after the application 

 of the stimulus to the nerves, as to lead him to the conclusion that it was a 

 direct effect, and not secondary to contraction of the bloodvessels, and of the 



1 Experiments made like those of Pincus, Budge, Adrian, and Lamansky, with a 

 view of determining the functions of the coeliac and mesenteric plexuses hy noticing 

 the effects of their ablation can scarcely be of any service, since the operation re- 

 quired is accompanied by much hemorrhage and is so severe as to cause death in a. 

 few hours. However, the chief phenomena observed have been congestion, and 

 ecchymoses in the mucous membrane of the stomach and small intestine, with hyper- 

 secretion of mucus, liquid lieces, and more or less severe peritonitis. M. Morean, 

 Comptes Kentlus, 1868, p. 554, has shown that section of the nerves supplying a fold 

 of intestine leads to effusion into it. 



2 Houckgeest, Pfliiger's Archiv, 1873, Band vi, p. 266. 



3 Legros and Onimus, Robin's Journal de 1'Anat. et de la Physiologic, I860, p. 

 196, state that the application of interrupted currents of electricity to the pneumo- 

 gastrics produces relaxation and immobility of the intestines, whilst continuous cur- 

 rents exert but little action upon them. Sanders Ezn (Humphry and Turner's Jour- 

 nal of Anat., vol. vi, p. 242, 1872) states that irritation of the right pneiimogastrie 

 chiefly causes movement in the duodenum, and irritation of the left, movement in 

 the ilium. Goltz (Pfliiger's Archiv, 1872, p. 616) has shown that in the frog the 

 excitability of the myenteric ganglia is very greatly augmented when, by destruction 

 of the brain and spinal cord or section of the pneumogastrics, they are cut off from 

 the central nervous system, which therefore in this animal appears to exert an in- 

 hibitor}' influence upon them. 



4 Lister, Proceed. Roy. Soc , 1858 ; Nasse, Beitriige zur Physiologic der Darm- 

 bewegungen, 1866; Wu'ndt, Physiologic, 1873, p. 191. 



5 See Ludwig and Spiess, Sitzungsberichte d. k. Akad. der Wiss zu Wien, B. xxv, 

 1857, p. 580; Kolliker; Houckgeest, Pfliiger's Archiv, B. vi, p 266; and others. 



