EPIGASTRIC OR SOLAR PLEXUS. 451 



near the oesophagus ; and the right nerve will be seen at a corresponding 

 point on the opposite aspect. Branches from the right nerve are to be 

 followed to the plexus of the sympathetic by the side of the coeliac axis, 

 and from the left, to the hepatic plexus. 



The EPIGASTRIC or SOLAR PLEXUS is a large network of nerves and 

 ganglia, which lies in front of the aorta and the pillars of the diaphragm : 

 it fills the space between the suprarenal capsules of opposite sides, and 

 extends downwards to the pancreas, surrounding the coeliac axis and the 

 superior mesenteric artery. The plexus is connected on each side with 

 the large and small splanchnic nerves ; and it is joined also by an offset 

 of the right pneumo-gastric nerve. Large branches are furnished to the 

 different viscera along the vessels. 



The semilunar ganglia, one on each side, are the largest in the body, 

 and each is joined at the upper end by the great splanchnic nerve. Each 

 is situate at the outer part of the plexus, close to the suprarenal body, and 

 on the pillar of the diaphragm : the ganglion on the right side is beneath 

 the vena cava. Irregular in shape, the mass is oval, or divided into 

 smaller ganglia : from its outer side nerves are directed to the kidney and 

 the suprarenal capsule. 



Offsets of the plexus. The nerves supplied to the viscera form plexuses 

 around the vessels ; thus there are coeliac, mesenteric, renal, spermatic, 

 diaphragmatic, &c. 



Diaphragmatic plexus. This plexus comes from the upper part of the 

 semilunar ganglion, but it soon leaves the artery to enter the substance of 

 the diaphragm : a communication takes place between the phrenic nerve 

 of the cervical plexus (p. 80) and these branches of the sympathetic. On 

 the right side is a small ganglion where the plexus is joined by the spinal 

 nerve ; and from it filaments are supplied to the vena cava and the supra- 

 renal body. The ganglion is absent on the left side. (Swan.) 



The suprarenal nerves are very large and numerous, in comparison with 

 the size of the part supplied, and are directed outwards to the suprarenal 

 body. One of the splanchnic nerves communicates with this plexus. 



The renal plexus is derived from the semilunar ganglion and outer part 

 of the plexus, and is joined by the smallest splanchnic nerve. The nerves 

 surround the renal artery, having small ganglia on them, and enter the 

 kidney with the vessels. An offset is given from the renal to the sper- 

 matic plexus (p. 443). 



The coeliac plexus is a direct continuation of the plexus around its artery : 

 it is joined by the small splanchnic nerve on each side, and by an offset 

 from the right pneumo-gastric nerve. The plexus divides like the artery 

 into three parts coronary, splenic, and hepatic. 



a. The coronary plexus accompanies the vessel of the same name to the 

 upper border of the stomach, where it ends : it communicates with the left 

 vagus nerve. 



b. The splenic plexus furnishes offsets to the pancreas, and to the 

 stomach along the left gastro-epiploic artery : and it is joined by an offset 

 from the right pneumo-gastric nerve. 



c. The hepatic plexus is continued on the vena portas, the hepatic artery, 

 and the bile duct into the liver, and ramifies on those vessels : in the small 

 omentum, the plexus is joined by offsets from the left vagus. The follow- 

 ing secondary plexuses are furnished around the branches of the hepatic 

 artery, and have the same name and distribution as the vessels : 



A pyloric plexus is distributed along the upper border of the stomach. 



