CERTAIN SETS OF NERVES 



93 



many similar relations are being gradually worked out clinically. Landois 

 gives the following as the general spinal distribution of the viscera: The 

 heart and lungs are represented by the tenth cranial and by the upper 

 thoracic nerves; the stomach, small intestine, liver, spleen, and pancreas 

 by the vagus and the middle inferior thoracic and upper lumbar nerves; 

 the adrenals, kidneys, testicles, ovaries, and uterus by the middle and 

 lower thoracic and the upper lumbar nerves; the rectum, prostate, penis, 

 uterus, and vagina by the sacral nerves and the hypogastric plexus, which 

 last in turn is supplied from the lower dorsal and upper lumbar cord. 

 In certain animals some motor fibers pass out through the dorsal roots 

 (Morat and Bonne) and in some mammals the vaso-dilators, for certain 

 parts at least, go by the same unsymmetrical paths. If these conditions 

 obtain in man, however, their details have not as yet been made out. 



FIG. 47 



Diagram of the neurones of a spinal ganglion, showing their relations: p.r., posterior root; 

 a.r., anterior root; p.s., posterior branch, and a.s., anterior branch of a spinal nerve; w.r., white 

 ramus communicans; a, large, and 6, small spinal ganglion cells with bifurcations; c, one of 

 Dogiel's types of ganglion cells; s, multipolar cell; d, nerve-fiber from a sympathetic ganglion 

 terminating in pericellular plexuses. (Dogiel and Bohm, and Davidoff and Huber.) 



In Plate IV is given the distribution of the spinal posterior roots, accord- 

 ing to Kocher as he finds it indicated by human pathological inquiry, the 

 two halves of the picture representing respectively the front and the back 

 of a man. A similar map made by Head mostly corresponds. 



The Sympathetic Nerves. The quasi-system of neural structures known 

 by the name sympathetic, consists of three sets of ganglia and the fibers 

 connecting and serving them. The first set of ganglia are those of the 

 gangliated cord, about twenty-two in number on each side. They extend 

 from the base of the skull to the coccyx, and are classed as cervical, 

 dorsal, lumbar, and sacral. The second set are the ganglia (solar, hypo- 

 gastric, pelvic, etc.) of the prevertebral plexuses. The third set are the 

 much smaller peripheral groups of cells situated in the various viscera 

 (e. g., in the plexuses of Auerbach and the no less essential ganglia of the 



