140 ANTHROPOLOGY. 



and others with the third and fourth. The internal branches are pha- 

 ryngeal, laryngeal, and cardiac. The pharyngeal arise from the superior 

 part of the ganglion ; are of a pale red color and ganglionic structure ; they 

 pass inwards and join the pharyngeal branches of the glosso-pharyngeal and 

 pneumogastric in the extensive plexus which supplies the pharynx and 

 fauces. The laryngeal branches arise near the last, pass downwards and 

 inwards, and join the branches of the superior laryngeal nerve. The supe- 

 rior cardiac^ or superficialis cordis, arises near the lower part of the gan- 

 glion, and descending, enters the chest, and joins the great cardiac ganglion. 



The middle cervical ganglion, smaller than the superior, is sometimes 

 wanting. It is situated behind the carotid opposite to the fifth vertebra; 

 from its anterior aspect it sends off the middle or great cardiac nerve, 

 which enters the chest, and with the superior and inferior cardiac nerves 

 joins the cardiac plexus and ganglion. 



The inferior cervix^al ganglion is of an irregular figure, semilunar or 

 triangular, and frequently appears to consist of several small ganglions con- 

 nected with each other by reddish filaments. It is situated between the 

 transverse process of the last cervical vertebra and the neck of the first 

 rib; filaments from it communicate with the phrenic nerve and with the 

 brachial plexus ; its external branches join the three last cervical and first 

 dorsal nerves. From its inferior aspect proceed the inferior cardiac nerves, 

 which communicate with the middle, and with branches form the vagus 

 and recurrens, ending in the cardiac plexus. 



Cardiac Nerves, Ganglion, and Plexus. The superior cardiac nerve 

 arises from the inner part of the superior cervical ganglion, and descends 

 to the chest communicating with various nerves, and ultimately joining the 

 cardiac plexus, the recurrens, and other nerves. The middle cardiac nerve 

 arises from the middle cervical ganglion, or from the sympathetic nerve 

 about the middle of the neck; it descends either in a single cord or in 

 several parallel filaments into the thorax, where it is joined by large 

 branches from the vagus and recurrens nerves ; continuing its descent it 

 terminates in the cardiac ganglion or plexus. The inferior cardiac nerve 

 or nerves proceed from the inferior cervical ganglion, and terminate either 

 on the fore part of the aortic arch, or in the anterior cardiac plexus. 



The cardiac ganglion is situated within the arch of the aorta ; it is 

 joined by the right and left superior cardiac nerves, and by branches from 

 the pneumogastric. 



The great cardiac plexus is situated behind the ascending aorta, and 

 consists of a plexus of nerves formed by the middle and inferior nerves 

 from opposite sides, also by branches from the eighth pair, and the recur- 

 rent nerves. The roots of the large vessels and the structure of the heart 

 are supplied by the branches from the great cardiac ganglion and plexus, and 

 from the cardiac nerves. These branches form two smaller plexuses, the 

 anterior cardiac or coronary, and the posterior plexus. 



In the thorax the sympathetic nerves have twelve ganglions on each side 

 of the spine ; sometimes but eleven, when the last cervical and first dorsal 

 are united into one. Each of the thoracic ganglions is small, fiat, and tri- 

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