168 



Sympathetic Nerves: 



7. M. TRIGEMIM. 



7T. 



IT: 



512. The Communication of the Carotid Plexus with 

 some of the Cranial Nerves, After Eiidinger. 



The sympathetic nerve, N. sympafheticus, consists of a series 

 of ganglia, connected together by intervening cords, and of a number 

 of plexuses. 



The cervical portion of the sympathetic, Pars cervicalis 

 N. sympathies, consists of three ganglia on each side. The superior 

 is the largest, the middle is sometimes absent, the inferior is fre- 

 quently joined with the first thoracic ganglion. The latter gives off the 

 inferior cardiac nerve, N. cardiacus inferior., to the deep cardiac 

 plexus, the middle gives off the middle cardiac, N. cardiacus medius. 



The thoracic portion of the sympathetic, Pars tlioracica 

 N. sympatldcij consists of eleven thoracic ganglia, which communicate 

 with each other and with the intercostal nerves ; they strengthen the 

 thoracic plexuses. The first thoracic ganglion gives off the N. cardiacus 

 imus to the cardiac plexus. The two splanchnic nerves, Nervi 

 splanchnici, pass to the plexuses of the abdomen. 



The lum bo-sacral portion of the sympathetic, Pars 

 lumbo-sacralis N. sympathici has four or five lumbar ganglia, Ganglia 

 lumbalia, and the same number of s a c r a 1 ganglia, Ganglia sacralia, which 

 are connected with the lumbar nerves. They supply the plexuses of the 

 abdomen, the Ganglia sacralia also the Plexus Itypogastricus inferior. At 

 the coccyx, the two gangliated cords converge, and are connected by 

 means of a loop, in which a single ganglion, Ganglion coccygeum impar, 

 is found. 



The plexuses of the sympathetic nerve are formed not only 

 by the sympathetic , but also by the cranial and spinal nerves. The 

 cranial plexuses are : the Plexus caroticus interims (called in the 

 cavernous sinus : Plexus cavernosus) and the Plexus caroticus externus. 



