336 



DISSECTION OF THE ABDOMEN. 



General dis 

 position of 

 nerves. 



Two large 

 centres, 



epigastric 



and hypo- 

 gastric. 



How to lay 

 bare solar 

 plexus, 



and the 



semilunar 



ganglia. 



Follow the 

 ending of 

 the vagus 

 nerves. 



Solar 

 plexus : 



appearance 

 and extent : 



SYMPATHETIC AND VAGUS NERVES. 



SYMPATHETIC NERVE. In the abdomen, as in the thorax, the 

 sympathetic nerve consists of a gangliated cord on each side of the 

 vertebral column, and of prevertebral centres or plexuses, which 

 furnish branches to the viscera. 



The chief prevertebral plexuses in the abdomen are the epigastric 

 or solar and the hypogastric. The epigastric plexus is placed 

 behind the stomach, and supplies nerves to all the viscera above the 

 cavity of the pelvis : it is continued downwards to the hypogastric 

 plexus by the aortic plexus (p. 319). The hypogastric plexus dis- 

 tributes nerves to the pelvic viscera, and has already been noticed 

 at its commencement (p. 319). 



The knotted or gangliated cord will be met with in a subsequent 

 stage of the dissection ; and only the great solar plexus with its 

 offsets is to be now examined. 



Dissection. To denude the epigastric plexus, the following 

 dissection is to be made : The air should be let out of the stomach 

 and duodenum ; the portal vein, the common bile-duct, and the 

 gastro-duodenal artery are to be cut through near the pylorus ; and 

 the stomach, duodenum, and pancreas are to be drawn over to the 

 left side. On raising the liver, the vena cava appears ; this is to 

 be cut across above the junction of the renal veins with it, and the 

 lower end is to be drawn down with hooks. 



Beneath the vein the dissector will find the large reddish semi- 

 lunar ganglion of the right side ; and mixed up with the nerves of 

 the plexus are numerous lymphatic glands (coeliac glands), with a 

 dense tissue, which require to be removed with care. From its 

 inner part he can trace the numerous nerves and ganglia around the 

 cceliac and superior mesenteric arteries, and the secondary plexuses 

 on the branches of those arteries. From the outer part of the ganglion 

 offsets are to be followed to the kidney, the suprarenal body, and 

 the diaphragmatic arteries. At its upper end the junction with the 

 large splanchnic nerve may be seen ; and deeper than the last, one 

 or two smaller splanchnic nerves may be found as they issue through 

 a fissure of the diaphragm, and enter the coeliac, renal and supra- 

 renal plexuses. 



The student should then trace the ending of the pneumo-gastric 

 nerves on the stomach. The left nerve will be found at the small 

 curvature in front, near the oesophagus ; and the right nerve will 

 be seen at a corresponding spot on the opposite aspect. Branches 

 from the right nerve are to be followed to the plexus of the sympa- 

 thetic 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 pillars of the 

 diaphragm, and behind the pancreas and inferior cava : it fills the 

 space between the suprarenal capsules of opposite sides, and sur- 

 rounds the coeliac axis and the superior mesenteric artery. The 



