SYMPATHETIC NERVOUS SYSTEM. 



235 



tenth, and eleventh cranial nerves, 

 nerve end, as preganglionic fi- 

 bers, in the ciliary ganglion. 

 Their postganglionic fibers 

 leave this ganglion in the short 

 ciliary nerves and innervate 

 the plain muscle of the sphinc- 

 ter of the iris and the ciliary 

 muscle. The fibers that emerge 

 in the seventh and ninth 

 nerves probably supply the 

 glands and blood-vessels (vaso- 

 dilator fibers) of the mucous 

 membrane of the nose and 

 mouth. Some of these fibers 

 reach the fifth nerve by way 

 of anastomosing branches and 

 are .distributed with it. Their 

 preganglionic portion termi- 

 nates in some of the ganglia 

 belonging to the sympathetic 

 type which are found in this 

 region, such as the sphenopal- 

 atine and otic ganglia, and the 

 submaxillary and sublingual 

 ganglia for the fibers dis- 

 tributed to the glands of the 

 same name. The autonomic 

 fibers that arise with the tenth 

 (and the eleventh) nerves are 

 distributed through the vagus. 

 Physiologically these fibers 

 consist of motor fibers (vis- 

 ceromotor fibers) to the mus- 

 culature of the esophagus, 

 stomach, small intestine, and 

 large intestine as far as the 

 descending colon, motor fibers 

 to the bronchial musculature, 

 inhibitory fibers to the heart, 

 and secretory fibers to the 

 gastric and pancreatic glands. 

 The ganglia in which the pre- 

 ganglionic portion ends have 

 not been definitely isolated, 



Those that emerge in the third 



Fig. 105. Diagram giving a schematic 

 representation of the course of the autonomic 

 (sympathetic) fibers arising from the thoraci co- 

 lumbar and sacral regions of the cord. The 

 preganglionic fiber is represented in red, the 

 postganglionic in black lines. The arrows in- 

 dicate the normal direction of the nerve im- 

 pulses or nerve conduction. S.c., Superior 

 cervical ganglion; I.e., inferior cervical gan- 

 glion; T, the first thoracic ganglion; Sp., the 

 splanchnic nerve; C., the semiTunar or celiac 

 ganglion ; m., the inferior mesenteric ganglion ; 

 h., the hypogastric nerves; N.E., the nervus 

 erigens. The numerals indicate the corre- 

 sponding spinal nerves. 



