THE AUTONOMIC NERVOUS SYSTEM 



471 



(3) The abdominal viscera receive fibres from the lower six dorsal nerves 

 and the upper three or four lumbar. Most of these fibres run through the 

 sympathetic chain without making any connection with the ganglia, and 

 have their cell stations in the collateral ganglia of the selar plexus, the semi- 

 lunar and superior mesenteric ganglia. On their way to these ganglia they 

 form the greater and lesser splanchnic nerves. Their functions are : 



Vaso-constrictor for stomach and small intestine, kidney, and spleen. 

 Probably vaso-dilator for the same viscera. 



Inhibitory for both muscular coats of stomach and small intestine. 

 Motor for ileocolic sphincter. 



(4) The pelvic viscera are supplied by the lower dorsal and upper three 

 or four lumbar nerve roots. These fibres also pass by the main chain to 



Spinal cord 



r 



- Sympathetic chain 



---- Solar ganglion 



A. 



B. 



FIG. 240. Figure (after LANGLEY) to show the probable mode of connection 

 of ,the fibres of the splanchnic nerve with nerve-cells. 



A, usual type, all the fibres passing through the lateral chain to end 

 in the collateral ganglia of the solar plexus ; B, alternative condition, in 

 which a small minority of the fibres have their cell-stations in the sym- 

 pathetic chain. The pre-ganglionic fibres are black, the post-ganglionic red. 



make connections with the cells, chiefly in the inferior mesenteiic ganglia. 

 They convey : 



Vaso-constrictor impulses to pelvic viscera. 



Inhibitory fibres to colon (both coats). 



Motor and also inhibitory fibres to bladder. 



Motor fibres to retractor penis. 



Motor and inhibitory fibres to uterus and vagina. 



(5) The fore limb receives nerves from the white rami of the fourth 

 to the tenth thoracic nerves. All these fibres are connected with cells in the 

 stellate ganglion. They convey : 



Vaso-constrictor impulses to the blood vessels. 

 Secretory nerves to the sweat glands. 



(6) The hind limb is supplied by the nerve roots from the eleventh 

 thoracic to the third lumbar inclusive. The cell stations of these fibres 



