632 



SYMPATHETIC NERVE. 



FIG. 203. 



and sigmoid flexure of the colon. It sends off filaments 



called the hcemorrhoidal plexus, which follow the heemor- 



rhoidal arteries to the rectum. 



The lumbar ganglia are four or five in number, situated 



upon the bodies of the lumbar vertebras, and connected 



with the thoracic by a 

 cord which descends be- 

 hind the diaphragm close 

 to the spine to join the 

 first lumbar ganglion. 

 These ganglia also send 

 off external and internal 

 branches. The external 

 communicate by two or 

 three branches with the 

 lumbar nerves. The in- 

 ternal surround the aorta, 

 forming the 



Aortic Plexus. This 

 plexus receives filaments 

 from the inferior mesen- 

 teric, and descends into 

 the pelvis, where, in front 

 of the sacrum, it forms 

 the hypogastric plexus. 

 This latter plexus com- 

 municates with the sacral, 

 and sends filaments to 

 the pelvic organs, which 

 will be noticed in another 

 place. 

 The thoracic spinal nerves (Fig. 14) are twelve in num- 



Fio. 203 represents the plexuses of the Sympathetic Nerve. I Dorsal gan- 

 glia of the sympathetic, with the roots of the great splanchnic nerve arising 

 from them, m Lesser splanchnic nerve, o Solar plexus. Renal plexus. 

 p Mesenteric plexus, q Lumbar ganglia, r Sacral ganglia, s Vesical plexus. 

 t Rectal plexus, u Lumbar plexus (spinal.) v Rectum, w Bladder. * 

 Pubis. y Crest of ilium, z Kidney, o o Aorta. 6 6 Diaphragm, c c Heart 

 and cardiac plexus, d d Larynx. 



