336 



ESSENTIALS OF PHYSIOLOGY. 



intestine. Stimulation of the sympathetic nerves causes inhibition of 

 the tone of the intestinal wall and cessation of the rhythmic movements. 

 Stimulation of the nervi erigentes causes contraction of the whole length 



FIG. 126. Passage of food along the large intestine after a 

 bismuth meal, as seen by means of X-rays. The numbers 

 refer to the hours after the meal was taken. ( Hertz. ) 



of the colon. The sympathetic is therefore inhibitory and the pelvic 

 visceral nerves are motor in function. 



As in the small intestine, there are ganglionated plexuses in the 

 intestinal wall, of which the myenteric, lying between the layers of the 

 muscular coat, is associated with the local reflex mechanism controlling 

 the movements of the bowel. 



