THE SYMPATHETIC NERVE. 485 



Of the Solar Plexus. 



The Semi-lunar Ganglion, situated, as mentioned, en the side 

 of the aorta, is somewhat semicircular or oval, and is about an 

 inch long; its form, however, is much diversified in different 

 subjects. The several ganglions of which it is composed, are 

 frequently fused into a single one. That of the right side is 

 more voluminous than the other, and is placed between the 

 ascending vena cava and the crus of the diaphragm, somewhat 

 above the right renal artery. That of the left is situated upon 

 the left crus of the diaphragm, somewhat below the splenic ar- 

 tery. Between their inferior extremities, there are generally 

 two or three smaller ganglions. 



These several ganglions are united by numerous filaments, 

 which send out many ramifications, and anastomose freely with 

 each other. 



The preceding arrangement may be considered as the root 

 of the Solar Plexus, which extends from the cceliac artery to 

 the lower margin of the emulgents, and as it is common to the 

 ganglions of the two sides, it is an inch and a half or two inches 

 wide. Bichat has very properly remarked, that this plexus 

 seems to exist for the aorta, as all the divisions which it sends 

 out follow so exactly the branches of this artery, that we are 

 forced to adopt the latter as the basis of the description. The 

 intertexture and the number of the branches emanating from 

 the solar plexus are so complicated, that a description of indi- 

 vidual branches would be almost endless, as well as unintelli- 

 gible; anatomists are, therefore, generally agreed to describe 

 the plexus according to the order of the arteries which its de- 

 tachments adhere to and surround. 



1. The Diaphragmatic Plexus consists of a few filaments 

 coming from the superior part of the solar, and following the 

 course of the phrenic arteries. Some of them anastomose with 

 the terminating filaments of the phrenic nerve, in the thickness 

 of the diaphragm, 



2. The Plexus which surrounds the C&liac Artery, like it, is 



42* 



