THE NERVOUS SYSTEM 



Postganglionic neurons: Cells in the intrinsic gastric ganglia, fibers 

 to end in the gastric musculature. 



Function: Excites peristalsis. 

 (6) Gastric thoracicolumbar pathway. 



Preganglionic neurons: Cells in the intermediolateral column of the 

 spinal cord, fibers by way of the white rami from the fifth or sixth to 

 the twelfth thoracic nerves, through the sympathetic trunk without 

 interruption, and along the splanchnic nerves to the celiac ganglion, 

 where they end. 



Postganglionic neurons: Cells in the celiac ganglion, fibers by way 

 of the celiac plexus and its offshoots to the stomach, to end in the 

 musculature of the stomach. 



Function: Inhibits peristalsis. 

 5. Paths for the efferent innervation of the musculature of the urinary 



bladder, 

 (a) Vesical craniosacral pathway. 



Preganglionic neurons: Cells in the lateral part of the anterior 

 gray column in the sacral portion of the spinal cord, fibers by way 

 of the second and third sacral nerves and their visceral rami through 

 the pelvic plexus to the plexus upon the wall of the bladder. 



Postganglionic neurons: Cells in the small ganglia of the vesical 

 plexus, fibers to the vesical musculature. 



Function: Excites contraction of the vesical musculature exclusive 

 of the internal sphincter (trigonal area), the contraction of which it 

 inhibits and thus produces urination. 

 (6) Vesical thoracicolumbar pathway. 



Preganglionic neurons : Cells in the caudal part of the intermedio- 

 lateral cell column, fibers by way of the lower white rami to the infe- 

 rior mesenteric ganglion. 



Postganglionic neurons: Cells in the inferior mesenteric ganglion, 

 fibers through the inferior mesenteric plexus to the musculature of 

 the bladder. 



Function: Excites contraction of the internal sphincter (trigonal 

 area of the vesical musculature), causing retention of urine. 

 It will be noted that the viscera receive a double autonomic innervation, and 

 that the impulses transmitted along the craniosacral pathways are usually 

 antagonistic to those transmitted along the thoracicolumbar paths. 



