NERVES OP THE NECK. 



515 



FIG. 155. 



and automatic, have all been applied 

 to it. 



The sympathetic is not a single 

 nerve, hut consists of two cords extend- 

 ing from the hase of the cranium to 

 the coccyx. Each of these cords de- 

 scends along the neck anterior to the 

 vertebras, behind the carotid artery 

 and jugular vein, and in front of the 

 rectus-capitis and longus colli muscles. 

 In the chest they are traced along the 

 sides of the spine, over the heads of 

 the several ribs, and are found enter- 

 ing the abdomen beneath the true lig- 

 amentum arcuatum. They descend on 

 the anterior part of the lumbar ver- 

 tebras, between the psoas muscles and 

 crura of the diaphragm, into the pel- 

 vis ; they pass along the anterior sur- 

 face of the sacrum to the first bone 

 of the coccyx, where the two cords 

 unite in a small ganglion, called coc- 

 cygeal or ganglion impar. 



Throughout the whole course of 

 these nerves a series of knots or ganglia 

 are observed, named according to their situation, cervical, 

 dorsal, lumbar, and sacral; there being three cervical, 

 twelve dorsal, five lumbar, and three sacral. 



FIG. 155 represents the Sympathetic Nerve its entire length. 1 Superior 

 cervical ganglion. 2 Its ascending branch. 3 Descending branch. 4 Exter- 

 nal branches connecting with the first, second and third cervical nerves. 5 

 Internal branches connecting with the eighth, ninth and facial nerves. 6 Su- 

 perior cardiac nerve. 7 Middle cardiac nerve. 8 Inferior cardiac nerve, 

 coming successively from the first, second and third cervical ganglia. 9 First 

 dorsal ganglion. 10 Last dorsal ganglion. 11 Spinal nerves. 12 Great 

 splanchnic nerve. 13 Semilunar glangia forming the solar plexus. 14 Lesser 

 splanchnic nerve, going to the renal plexus. 15 Branches from the lumbar 

 ganglia. 16 Hypogastric plexus. 17 Sacral ganglia. 18 Ganglion impar or 

 last ganglion of the sympathetic. 



