376 HEALTH AND DISEASE 



Cervical Sympathetic. The cervical sympathetic consists of two 

 large ganglia united by an intervening cord. The ganglia are distin- 

 guished as the superior and the inferior cervical. Sometimes there are 

 three. The superior cervical ganglion, situated beneath the atlas, gives 

 branches to those nerves in its vicinity the glosso-pharyngeal, spinal 

 accessory, pneumogastric and hypoglossal, and the lower branch of the 

 first cervical nerve. 



The efferent branches, or those which pass from the ganglion, are fila- 

 ments to the internal carotid artery, others to the three divisions of the 

 common carotid, and to the guttural pouch and pharynx. The branches 

 which accompany the internal carotid into the cranium form the carotid 

 and cavernous plexuses, and are connected with the fifth cranial nerve. 



The sympathetic cervical cord passes down the neck in company with 

 the pneumogastric, which it leaves on entering the chest and joins the 

 inferior cervical ganglion. In its course down the neck no filaments are 

 received or given off by it. 



The Inferior Cervical Ganglion. As we have already pointed out, 

 this is sometimes double, the two being joined together by a short grayish 

 band. When this condition exists, the portion in front, which is always 

 the smaller, is known as the middle cervical ganglion. 



The afferent branches, or those which go to the ganglion, are two in 

 number, one resulting from the union of small filaments from the second, 

 third, fourth, fifth, sixth, and seventh pairs of cervical nerves, and the 

 other derived from the eighth cervical nerve. 



The efferent branches of the inferior cervical ganglion are mainly dis- 

 tributed to the heart. Some very fine filaments may also be seen to 

 enter the anterior mediastinum, or proceed to the branches of the brachial 

 trunk. 



The Dorsal Sympathetic Chain. When the inferior cervical ganglion 

 has given branches to the heart, the dorsal sympathetic chain is continued 

 on from it in a backward direction, between the costo-vertebral articu- 

 lation and the pleura. 



As it passes backwards there appears upon it a number of very small 

 ganglia, one of which is situated against each of the vertebral openings 

 through which pass the spinal nerves. 



Each ganglion receives one or two small afferent filaments from the 

 inferior branches of those nerves. 



In its course backwards it gives off the great splanchnic nerve at a 

 point corresponding to the seventh intercostal space. From this point 

 it proceeds backwards, and in its course receives a small branch from each 

 of the ganglia. 



