THORACIC NEEVES AND GANGLIA. 635 



Fig. 334. — DiAGEAJiMATic View of the Sympathetic Cord of the Rkset Sire, 

 SHOWING ITS Connections with the Principal Cerebko-Spinal Nerves and thk 

 Main Preaortic Plexuses. J 



Cen^-o-spinal Nerves. — VI, a portion of the sixth cranial nerve as it passes through 

 the cavernous sinus, receiving two twigs from the carotid plexus of the sympathetic 

 nerv3 ; 0, ophthalmic ganglion connected by a twig with the carotid plexus ; ]M, con- 

 nection of the spheno-palatine ganglion by the Vidian nerve with the carotid plexus ; C, 

 cervical plexus ; Br, brachial plexus ; D 6, sixth iuteixostal nerve ; D 12, twelfth ; L3, 

 third lumbar nerve ; S 1, first sacral nerve ; S 3, third ; S 5, fifth ; Cr, anterior crural 

 nerve ; Cr', gi-eat sciatic ; ^^n, pneumo-gastric nerve in the lower part of the neck ; r, 

 recuiTcnt nerve winding round the subclavian artery. 



Sympatlietic Cord — c, superior cervical ganglion ; c', second or middle ; c", inferior ; 

 from each of these ganglia cardiac nerves (all deep on this side) are seen descending to 

 the cardiac plexus ; f^ 1, fjlaced immediately below the first dorsal sympathetic ganglion ; 

 d 6, is opposite the sixth ; I 1, first lumbar ganglion ; c y, the terminal or coccygeal 

 ganglion. 



Preaortic and Viseeral Plexuses. — p p, pharyngeal, and, lower down, laryngeal 

 plexus ; pi, posterior pulmonary plexus spreading from the pneumo-gastric on the back 

 of the right bronchus ; c a, on the aorta, the cardiac plexus, towards which, in addition 

 to the cardiac nerves from the three cervical sympathetic ganglia, otlier branches are seen 

 descending from the j)neumo-gastric and recurrent nerves ; c o, right or posterior, and c o, 

 left or anterior coronary plexus ; o, oesophageal plexus in long meshes on the gullet ; sp, 

 great splanchnic nerve formed by branches from the fifth, sixth, seventh, eighth, and 

 ninth dorsal ganglia ; +, small splanchnic from the ninth and tenth ; + +, smallest or 

 third splanchnic from the eleventh : the first and second of these are shown joining the 

 solar jjlexus, so; the third descending to the renal plexus, re; connecting branches 

 between the solar plexus and the pneumo-gastric nerves are also represented ; p n', above 

 the place where the right pneumo-gastric passes to the lower or posterior surface of the 

 stomach ; p n", the left distributed on the anterior or upper surface of the cardiac portion 

 of the organ : from the solar plexus large branches ai-e seen surrounding the arteries of 

 the coeliac axis, and descending to m s, the suijerior mesenteric plexus ; opposite to this 

 is an indication of the suprarenal plexus ; below re (the renal plexus), the spermatic 

 plexus is also indicated ; « o, on the front of the aorta, marks the aortic plexus, formed 

 by nerves descending from the solar and superior mesenteric plexuses and from the lumbar 

 ganglia ; in i, the inferior mesenteric plexus surrounding the corresijonding artery ; h y, 

 hyjjogastric plexus placed between the common iliac vessels, connected above with the 

 aortic plexus, receiving nerves from the lower lumbar ganglia, and dividing below into the 

 right and left pelvic or inferior hypogastric plexuses ; p I, the right pelvic plexus ; from 

 this the nerves descending are joined by those from the plexus on the superior hemor- 

 rhoidal vessels, m i', by sympathetic nerves from the sacral ganglia, and by numerous 

 visceral nerves from the third and fourth saeral spinal nerves, and there are thus formed 

 the rectal, vesical, and other plexuses, which ramify upon the viscera from behind for- 

 wards, and from below upwards, as towards i r, and v, the rectum and bladaer. 



and ligaments. Several of these branches enter the posterior pulQionary 

 plexus. 



The branches furnished by the loiver six or seven ganglia unite into 

 three cords on each side, which pass down to join plexuses in the 

 abdomen, and are distinguished as the great, the small, and the smallest 

 splanchnic nerve. 



The Great Splanchnic Nerve. — This nerve is formed by the union 

 of small cords (roots) given off by the thoracic ganglia from the fifth or 

 sixth to the ninth or tenth inclusive. By careful examination of speci- 

 mens after immersion in acetic or diluted nitric acid, small filaments 

 may be traced from the splanchnic roots upwards as far as the third 

 ganglion, or even as far as the first (Beck, in the " Philosophical Trans- 

 actions," Part 2, for 1846). 



Gradually augmented by the successive addition of the several roots, 

 the cord descends obliquely inwards over the bodies of the dorsal 

 vertebras ; and, after perforating the crus of the diaphragm at a variable 



