THE GREAT SYMPATHETIC CORDS. 



627 



the ganglia are connected by interven- 

 ing cords. These cords are placed s}Tn- 

 metrically in fi-ont of the vertebral 

 column, and extend from the base of 

 the skull to the coccyx. Superiorly they 

 are connected with plexuses which enter 

 the cranial cavity, while inferiorly they 

 converge on the sacrum, and terminate 

 in a single ganglion on the coccyx. The 

 several portions of the cords are dis- 

 tinguished as cervical, dorsal, lumbar, 

 and sacral, and in each of these parts 

 the ganglia are equal in number, or 

 nearly so, to the vertebra on which they 

 lie, except in the neck, where there are 

 only three. 



t«" 



Fig. 381. — Diagrammatic Outline of the Stm- 



PATHETIC COKD OF ONE SII>E IN CONNECTION 



WITH THE Spinal Nekves. 



Tlie full descriijtion of this figure will Le found 

 at p. 568. 



On the right side the following letters indicate 

 parts of the sympathetic nerves, viz. a, the superior 

 cervical ganglion, communicating with the upper 

 cervical spinal nerves and continued below into 

 the great sympathetic cord ; h, the middle cer- 

 vical ganglion ; c, d, the lower cervical ganglion 

 united with the first dorsal ; d' , the eleventh 

 doi'sal ganglion ; from the fifth to the ninth 

 dorsal ganglia the origins of the great splanchnic 

 nerve are shown ; I, the lowest dorsal or upper 

 lumbar ganglion ; ss, the upper sacral ganglion. 

 In the whole extent of the sympathetic cord, the 

 twigs of union with the spinal nerves are shown. 



Connection of fJte gangliaiecl cords 

 with the cereh-Q-spinal system. — The 

 ganglia are severally connected with the 

 spinal nerves in their neighbourhood by 

 means of short filaments ; each connect- 

 ing filament consisting of a white and a 

 grey portion, the former of which may 

 be considered as proceeding from the 

 spinal nerve to the ganglion, the latter 

 from the ganglion to the spinal nerve. 

 At its upper end the gangliated cord 

 communicates likewise with certain 

 cranial nerves. The main cords inter- 

 vening between the ganglia, like the 

 smaller filaments connecting the ganglia 

 with the spinal nerves, are composed of 

 a grey and a white part, the white being 

 continuous with the fibres of the spinal 

 nerves prolonged to the ganglia. 



s s 2 



