638 



DISSECTION OF DEEP VESSELS AND NERVES OF NECK. 



to external 

 carotid, 



forming 



canal communications are formed with the tympanic branch of the 

 glosso-pharyngeal nerve, and with the spheno-palatine ganglion ; 

 with the former near the lower end, and with the latter near the 

 upper opening of the canal. The communications and plexuses 

 which these nerves form in their course to the brain are described at 

 p. 518. 



Branches for blood-vessels (nervi molles). These nerves surround 

 the external carotid trunk, and ramify on its branches so as to form 

 plexuses on the arteries with the same names as the vessels : some 

 and X gangiia; small ganglia are occasionally found on these slender nerves. By 

 means of the plexus on the facial artery the submaxillary ganglion 

 communicates with the sympathetic ; and through the plexus on 

 the internal maxillary artery the otic ganglion obtains a similai 

 communication. 



topharyn- The pharyngeal nerves pass inwards to the side of the pharynx, 

 geal plexus ' where they join with the branches of the glosso-pharyngeal and 

 pneumo-gastric nerves in the pharyngeal plexus. 



Cardiac nerves enter the thorax to join in the plexuses of th( 

 heart. There are three cardiac nerves on each side, viz., superior 

 middle, and inferior, each taking its name from the ganglion c 

 which it is an offset. 



The superior or superficial cardiac nerve of the right side course 

 behind the sheath of the carotid vessels, and enters the thorax along 

 the innominate artery. In the neck the nerve is connected with 

 the cardiac branch of the vagus, with the external laryngeal, and 

 with the recurrent nerve. In some bodies it ends by joining one 

 of the other cardiac nerves. 



The MIDDLE CERVICAL or THYROID GANGLION is of Small S1Z6, 



and is situate beneath the great vessels, usually opposite the sixth 

 cervical vertebra, on or near the inferior thyroid artery. Its 

 branches are the following : 



Connecting branches with the spinal nerves sink between the 

 borders of the longus colli and anterior scalenus to join the fifth 

 and sixth cervical nerves. 



A considerable branch passes between the middle and inferior 

 loop to lower cervical ganglia, forming a loop (ansa Vieussenii) over the front of 

 ;anghon; ^ subclavian artery, and supplying it with filaments, 

 branches of Branches for distribution. These consist of nerves to the thyroid 

 body, together with the middle cardiac nerve. 



The thyroid branches ramify around the inferior thyroid artery, 

 and end in the thyroid body ; they join the external and recurrent 

 laryngeal nerves. 



The middle or great cardiac nerve descends to the thorax across 

 the subclavian artery ; its termination in the cardiac plexus has been 

 learnt in the chest (p. 473). In the neck it communicates with the 

 upper cardiac and recurrent laryngeal nerves. 



The INFERIOR CERVICAL GANGLION is of large si/e, but irregular 

 in shape, and lies over the interval between the first rib and the 

 transverse process of the last cervical vertebra, its position being 



to cardiac 

 plexuses ; 



superficial 



cardiac 



nerve. 



Middle 

 ganglion 



joined to 

 spinal 

 nerves ; 



distribution, 



thyroid 

 branches, 



middle 

 cardiac 

 nerve 



Inferior 

 ganglion 



