258 SPECIAL PHYSIOLOGY. 



the solar ganglion; it is joined also by a few terminal branches of the 

 pneumogastric nerves. The renal plexuses are derived partly from 

 the solar plexus, and partly from the lowest splanchnic nerves ; arid 

 lower down, are the hypogastric plexuses and their offsets. 



The branches proceeding from the various sympathetic ganglia and 

 plexuses, are thus distributed. The lenticular ganglion receives fibres 

 from the third, sixth, and fifth cranial nerves, and supplies branches 

 to the eyeball, especially destined for the iris, and for the bloodvessels, 

 including those of the ciliary processes. The otic ganglion, connect- 

 ed with the fifth and glosso-pharyngeal nerves, gives branches to a 

 muscle in the tympanum or middle ear, and thus probably assists in 

 the control of parts of the organ of hearing. The spheno-palatine 

 ganglion is connected with branches of the fifth and the facial nerves; 

 its branches may be traced to the mucous membrane of the nose and 

 palate, so that it may be considered as associated with the parts con- 

 cerned in the functions of taste and smell. The submaxillary ganglion, 

 which communicates with the fifth and facial nerves, sends its branches 

 chiefly to the submaxillary gland. The Gasserian ganglion on the 

 root of the fifth pair, also the ganglia on the trunks of the glosso- 

 pharyngeal and pneumogastric nerves, and, lastly, those found on the 

 posterior roots of the spinal nerves, if these be really sympathetic gan- 

 glia, as seems probable, must supply sympathetic nerve fibres, which 

 are blended with the fibres of the nerves on which they are respectively 

 placed, and are most likely distributed with them to various parts of 

 the body. 



Of the chief plexuses, the cardiac sends branches to the heart, Fig. 

 60, A, and to the great bloodvessels, and from these, others are con- 

 tinued on to the roots of the lungs, assisting in the formation of the 

 pulmonary plexuses. From the aorta, the sympathetic nerves are con- 

 tinued on to the great arteries, and so on to all the arteries of every 

 part of the body. From the solar plexus, proceed the branches to the 

 stomach, s, intestines, i, liver, kidneys, &, and.other abdominal viscera ; 

 each organ having a secondary plexus named accordingly. The hypo- 

 gastric plexus supplies the pelvic viscera and their bloodvessels. 



The ganglia of the sympathetic nerves are its proper centres ; they 

 consist of colored nerve cells, mostly, it is said, unipolar, or provided 

 with only one process ; they give origin to the proper sympathetic 

 nerve-fibres, which are nearly all of the gelatinous, or non-medullated, 

 kind (p. 52). But the cords which connect the trunks of the sympa- 

 thetic with the several cranial and spinal nerves, are whitish in color, 

 whiter even than the branches given off from the sympathetic to its 

 plexuses ; whilst the ultimate ramifications on the arteries are of a pale 

 pinkish hue. These last ramifications, which, as just mentioned, are 

 commonly supported upon the small arteries of the different parts to- 

 ward which they run, are composed of a few tubular fibres, mixed with 

 many of the non-medullated kind. They are often connected with, and 

 reinforced by, numerous additional minute ganglia : this is especially the 

 case in regard to the arteries of the viscera. In the limbs, sympathetic 

 nerve-fibres are probably blended with the cerebro-spinal nerves. .The 

 final destination of the sympathetic nerve-fibres, whether medullated or 



