DUCTS, VESSELS, AND NERVES, ETC. 177 



forates the diaphragm, then, by removing the peritoneum, each artery, 

 as it presents itself, is to be followed out by such means as the dis- 

 sector's ingenuity will suggest. The nerves will some of them be 

 exposed with the arterial trunks which they accompany ; a detailed 

 dissection of them is rarely accomplished ; being composed of plexuses 

 proper to each organ, they are usually made the subject of special 

 dissections. More than to trace, to some slight extent, the connection 

 of these plexuses with the principal ganglia of the sympathetic, can 

 hardly be expected. The student, therefore, need not be disappointed 

 if he is unable to verify those paragraphs marked with an asterisk. 



The nervous plexuses of the abdomen may be enumerated 



follows: 



Solar, Superior Mesenteric, 



Phrenic, Aortic, 



Supra-renal, Inferior Mesenteric, 



Gastric, Renal, 



Hepatic, Spermatic, 



Splenic, Hypogastric. 



In searching for the cceliac axis, which lies behind the 

 stomach, the SOLAR PLEXUS will be seen encircling the 

 coeliac axis, covering the aorta, and spreading out in all 

 directions; it is joined by the greater splanchnic nerve of 

 both sides (p. 122), and receives branches from the pneu- 

 mogastric and phrenic nerves. The solar plexus contains 

 a number of ganglia, the principal one of which is called 

 the SEMILUNAR GANGLION, and the radiation of nerves 

 from this gives the plexus its name of solar. From this 

 plexus arise those branches which form the phrenic and 

 supra-renal plexuses ; these may also be seen at this stage 

 of the dissection. 



The ABDOMINAL AORTA commences at the aortic opening 

 of the diaphragm, and, descending on the left side of the 

 vertebral column, terminates by dividing into the two com- 

 mon iliac arteries. 



The CCELIAC Axis is the first large trunk given off by 

 the abdominal aorta. The phrenic arteries are normally 

 the first, but they are extremely irregular in their origin, 

 and as often arise from the cceliac axis as from the aorta ; 

 they are two in number, and ascend obliquely outward, 

 ramifying on the under surface of the diaphragm ; their 

 inosculations with other arteries are very numerous, and 

 they send a branch to the supra-renal capsule on both sides. 

 The cceliac axis is a short but large trunk, which arises 

 close to the diaphragm and quickly divides into three 



