438 THE NERVOUS REGULATION OF THE BLOOD-VESSELS 



and that the stimulation of the intact plexus, or of its distal end, gives 

 powerful vasoconstrictor effects. It has also been established that 

 this plexus conducts afferently, because the excitation of its central 

 stump produces a pressor reaction. The same results may be obtained 

 by the stimulation of either splanchnic nerve; hence, the intestine is 

 innervated bilaterally. Moreover, Frangois-Frank and HalUon^ claim 

 that this preganglionic path embraces dilator fibers for this organ. 



The Vasomotors of the Stomach. — These fibers ascend from the 

 celiac ganglion of the solar plexus and follow in the paths of the three 

 branches of the celiac axis. By measuring the venous return from this 

 organ, Burton-Opitz^ has shown that its left side, as well as the region 

 along the greater curvature, is innervated by fibers which are derived 

 from the plexus gastrolienalis surrounding the artery of the same name. 

 Its pyloric portion, as well as the region of the lesser curvature, is 

 innervated by the plexus accompanying the arteria epiploica dextra, 

 while the pylorus proper receives its vasomotor supply by way of the 

 plexus hepaticus and the plexus gastroduodenalis. By stimulation 

 of the aforesaid nerves, it was possible to obtain most decided reduc- 

 tions in the blood supply of this organ. The same results followed 

 the stimulation of the splanchnic nerves. The vasomotor nerves for the 

 upper and middle segments of the duodenum are also derived from 

 the cehac ganglion. These fibers ascend, together with those for the 

 pylorus, by way of the hepatic plexus and the plexus gastroduodenaHs.* 



The Vasomotors of the Spleen. — These fibers are contained in the 

 plexus gastrolienalis which closely invests the artery of the same name. 

 By determining the blood flow through this organ by means of the 

 stromuhr, it has been shown by Burton-Opitz^ that the stimulation 

 of this plexus is followed by a constriction of the splenic blood-vessels. 

 The same result is obtained by stimulation of either splanchnic nerve. 

 Schaffer,^ who has made use of a splenic oncometer, states that this 

 preganglionic path includes vasodilators for this organ. 



The Vasomotors of the Pancreas. — These fibers arise in the celiac 

 ganglion and attain the aforesaid organ by way of the plexus hepaticus 

 and the plexus gastroduodenalis. It seems, however, that the caput 

 pancreatis is also innervated by fibers from the mesenteric plexus, and 

 that the cauda pancreatis receives fibers from the neighboring splenic 

 plexus. As far as the blood-vessels in the central mass of this organ 

 are concerned, it has been shown by Burton-Opitz^ that they are in- 

 nervated by fibers which ascend from the celiac ganglion by way of 

 the hepatic plexus and the plexus gastroduodenalis. 



The Vasomotors of the Liver. — This organ derives its blood supply 

 from two sources, namely, from the hepatic artery, a branch of the 



1 Archiv de Physiol., 1896, 493. 



2 Pfliiger's Archiv, cxxxv, 1908, 205. 



3 Burton-Opitz, Am. Jour, of Physiol., cxlvi, 1914, 344. 



4 Pfluger's Archiv, cxxix, 1908, 189. 



5 Jour, of Physiol., xx, 1896. 



8 Pfluger's Archiv, cxlvi, 1908, 344. 



