332 PRACTICAL ANATOMY. 



of the cardiac. It is distributed to the deep cardiac 

 plexus. The third or inferior cervical ganglion is placed 

 at the side of the seventh cervical vertebra, and rests on 

 the neck of the first rib. Its most important branch is 

 the inferior cardiac, and is distributed to the deep cardiac 

 plexus. 



The sympathetic ganglia of the thorax consist of 

 a chain of ganglia placed on either side of the spinal 

 column, resting on the heads of the ribs and covered 

 by the pleura. Their branches are distributed in 

 every direction. The most important are the greater 

 splanchnic, lesser splanchnic, and renal splanchnic. 

 The greater splanchnic arises by filaments from the lower 

 six dorsal ganglia. It is a nerve of considerable size, 

 white in color, descends, and pierces the crus of the 

 diaphragm, and terminates in the solar plexus. The 

 lesser splanchnic arises from the ninth and tenth gan- 

 glia, accompanies the greater splanchnic, and enters the 

 solar plexus. The renal splanchnic, often wanting, arises 

 from the lower two dorsal ganglia, and terminates in the 

 renal plexus. 



The solar plexus is a great sympathetic ganglion, 

 which surrounds the cceliac axis. It is formed by two 

 semilunar ganglia and connecting fibres, and these 

 receive the splanchnics and termination of the pneumo- 

 gastrics. The solar plexus sends branches in all directions 

 and forms retiform plexuses around all of the branches 

 of the abdominal aorta. It is through the blood-vessels 

 that the sympathetic reaches the viscera. 



The lumbar part of the sympathetic presents four 

 ganglia placed at the side of the spine, internal and pos- 

 terior to the psoas. Its branches are freely distributed 

 to the vessels and viscera. The sacral ganglia, four or 

 five in number, are placed along the inner line of the 



