1014 



THE NERVOUS SYSTEM 



with the abdominal aortic and superior mesenteric plexuses. It lies in the epigastric 

 region of the abdomen behind the bursa omentalis (lesser sac of the peritoneum) and 

 the pancreas, upon the crura of the diaphragm and over the abdominal aorta, and 

 around the origin of the coeliac and the superior mesenteric arteries. It occupies the 

 interval between the suprarenal bodies and extends downwards as far as the renal 

 arteries. It is formed by the great and the lesser splanchnic nerves of both sides, by 

 cceliac branches of the right vagus, and by filaments from the upper lumbar ganglia of 



FIG. 721. ABDOMINAL PLEXUSES OF THE SYMPATHETIC. (After Toldt, "Atlas of Human An- 

 atomy," Kebman, London and New York.) 



CCELIAC PLEXUS l.EI-'T V.\<irs XKRVK 



PHRENIC PLEXl'X 

 \ 



.RIGHT r.u;r.v XERVE 

 f 



Parlal 



HEPATIC.. 

 PLEXUS 



., SVPR. \JIES\L 



PLEXUS 



mflm PHRENIC 



<:A.\<;LION 



f GREAT SPLAN- 

 CIIS1C XERVE 



SUPERIOR 



MESE.\TKRIC 



PLEXUS 



- INFERIOR MEKEN- 

 TERIC PLE.\TH 



the sympathetic trunk. It sometimes receives co?liac branches from the left vagus. 

 It contains two large ganglia, the right and left cceliac (semilunar) ganglia (fig. 721). 

 The coeliac (semilunar) ganglia are two large, flat, irregularly shaped masses, 

 separable into a varying number of ganglia. These two masses, or rather the 

 smaller ganglia which compose them, are connected by a varying number of com- 

 municating branches. Each mass, right and left, lies upon the corresponding cms 

 of the diaphragm, at the inner border of the corresponding suprarenal body, being 

 sometimes overlapped by this body. The right mass lies behind the inferior vena 

 cava. Each coeliac ganglion receives at its upper border the greater splanchnic 



