MOVEMENTS OF THE INTESTINES 821 



by increased irritability and increased contractions (Fig. 344). On the 

 other hand, stimulation of the splanchnic nerves causes complete 

 relaxation of both coats of the small gut (Fig. 345). It seems that the 

 splanchnics normally exercise a tonic inhibitory influence on the 



FIG. 344. Effect of stimulation of right vagus on intestinal contractions. 



FIG. 345. Excitation of both splanchnic nerves. Balloon method. 

 Intestine returned to abdomen. 



intestinal movements, which can be increased by all manner of peri- 

 pheral stimuli. On this account it is often impossible to obtain any 

 movements in the exposed intestine so long as these remain in connec- 

 tion with the central nervous system through the splanchnic nerves. 

 The relaxed condition of the gut which obtains in many abdominal 

 affections is probably also reflex in origin, and is due to reflex inhibition 

 through the splanchnic nerves. 



As a result of the two sets of movements described above, the 



