396 ANATOMICAL TECHNOLOGY. 



phragm gives oflF another brancli, the N. splancJinicus Tninor. This 

 also penetrates the diaphragm and joins the semilunar ganglion 



(Fig. 90, 107). 



§ 1045. Ganglion semilunare (Fig. 90, 107). — The semilunar 

 gangUon belongs to the so called solar plexus of nerves, a network 

 of nerves formed partly from the vagus (§ 1041), but mostly from 

 the sympatMc. The ganglion is a slightly pinkish body situated 

 laterad of the origin of the superior mesenteric and cceliac arteries, 

 as shown in Fig. 107, and very near the adrenal body. It is quite 

 tough, and when grasped and pulled the nerves may be seen spread- 

 ing out in all directions like the rays of the sun. 



§ 1046. The abdominal sympathic. — In order to follow the 

 sympathic in the abdomen, the blood vessels should be removed. 

 The nervous cords of the two sides closely approach each other, so 

 that both may be traced at once. 



The caudal part of the sympathic is partly shown in Fig. 107, A, 

 and directions for tracing it are given under the preparation of this 

 figure. 



Preparation of Fig. 109. — Tlie arteries were injected with red and tte veins with blue 

 plaster (§§ 362, 363). The sternum was removed, and the thyroid and vertebral ganglia 

 of the sympathic and their branches isolated as directed above (§ 1008). The thyroid gan- 

 glion of the right side was displaced somewhat dextrad, the vertebral ganglion of the left 

 side drawn dorsad, and the muscles removed from the vertebra and the pleura and con- 

 nective tissue from the other parts. The oesophagus was slightly distended with cotton 

 and the two roots of the myelonal nerves slightly separated and held apart with cotton. 

 The preparation was hardened and preserved in alcohol (§ 286). 



Explanation of Fig. 109.— A. sbclv. sin., A. subclavia sinistra. A. sbdv. dext., 

 A. subclavia dextra — The right subclavian is shown in two places as if it were double ; 

 the artery is not double, but is shown in its natural position and also displaced in order to 

 more clearly indicate the ring of the sympathic {anscB s. annulus VieuSHenii) surrounding 

 it; see Fig. 108 and Foster, A, Fig. 37. A. c, A. carotidea (§ 900). A. sternalis— On the 

 left the name is written on the artery. A, thyr., A. vertebralis — By an inadvertence the 

 wrong abbreviation was used. The artery is shown on the right dorsad of the origin of 

 the A. sternalis. 



Alba — The white substance of the myelon. It is dotted to indicate the cut ends of 

 nerve fibers (§ 1048). 



Cn. centralis — The central canal of the myelon ; see Chapter X, Fig. 112, A. 



Centrum— The centrum or body of the 2d thoracic vertebra (§ 403). 



Cinerea — The gray or ganglionic substance of the myelon (§ 1047). It is left white in 

 the figure, and appears something like a letter H in the interior of the myelon (§ 998). 



F. dms., Fissura dorsimesalis — The dorsimesal (posterior) fissure of the myelon. 



F. vms., Fissura ventrimesalis — The ventrimesal fissure of the myelon. It is directly 

 opposite the dorsal fissure, and the two divide the myelon nearly in half (g 998). 



