78 ANATOMY FOE NURSES. [CHAP. VII. 



the sympathetic ganglia. 1 (The spinal ganglia will be con- 

 sidered later.) 



The sympathetic system. The sympathetic system consists of 

 a double chain of ganglia, placed on each side of the spinal 

 column, and united to each other by longitudinal filaments. 

 The fibres that arise from them are mostly of the non-medul- 

 lated variety. 



#er f 



FIG. 66. SECTION OF THE INTERNAL SAPHENOUS NERVE. Stained in osmic 

 acid and subsequently hardened in alcohol. Drawn as seen under a very low magni- 

 fying power. (G. A. S.) ep, epineurium, or general sheath of the nerve, consisting 

 of connective tissue separated by cleft-like areolse, which appear as a network of 

 clear lines, with here and there fat-cells,/, /, and blood-vessels, v ; per, perineurium, 

 or particular sheath of funiculus ; end, endoneurium, or connective tissue within 

 funiculus, embedded in which are seen the cut ends of the medullated nerve-fibres. 

 The fat-cells and the nerve-fibres are darkly stained by the osmic acid. 



These ganglia and nerves do not form an independent ner- 

 vous system, for each ganglion is connected by motor and sen- 

 sory fibres with the cerebral system. The sympathetic nerves 

 are distributed to the viscera and blood-vessels, of which the 

 movements are involuntary, and the general sensibility obtuse. 

 They form networks or plexuses upon the heart, about the 



1 Isolated ganglia are also found in the course of some of the cranial nerves, 

 and in some of the organs of special sense. 



