352 NEUROLOGY, OR ANATOMY OF NERVOUS SYSTEM 



and communicates with the facial. It escapes through the 

 auricular fissure, then divides into a branch to the auricle, 

 and a second which joins the posterior auricular. A recurrent 

 branch from the jugular ganglion supplies the dura mater 

 in the posterior fossa. 



(6) In the neck: A pharyngeal branch from the cervical 

 ganglion, deriving its fibers mainly from the spinal accessory, 

 crosses the internal carotid, and joins with the glossopharyngeal 

 and sympathetic in the pharyngeal plexus. This plexus supplies 

 the muscles and mucous membrane of the pharynx. 



The superior laryngeal, from the lower ganglion, runs internal 

 to the internal carotid vessels, receiving branches from the 

 pharyngeal plexus and sympathetic, and divides into the 

 external and internal laryngeal nerves. 



The external runs beneath the sternothyroid to supply the 

 cri co thyroid. It supplies the inferior constrictor, and sends 

 branches to the pharyngeal plexus and superior cardiac nerve. 



The internal branch pierces the thyrohyoid membrane to 

 supply the mucous membrane of the larynx, and by a long 

 branch joins a similar offset from the recurrent nerve behind 

 the ala of the thyroid cartilage. A twig supplies the aryte- 

 noideus. 



The inferior or recurrent laryngeal on the right side arises 

 in front of the subclavian artery and winds backward around 

 that vessel; on the left it rises in front of the arch of the aorta 

 and winds backward around it. Both nerves ascend between 

 the trachea and esophagus, behind the common carotid and 

 inferior thyroid arteries, to the lower border of the cricoid 

 cartilage. They enter the larynx beneath the inferior con- 

 strictor, supplying all its intrinsic muscles excepting the crico- 

 thyroid, and join the superior laryngeal. Each gives off cardiac 

 nerves which join those from the vagus and sympathetic; 

 trachcal and esophageal branches, and one to the inferior con- 

 strictor. 



The cervical cardiac nerves, two or three, are divided into 

 the superior, joining the cardiac branches of the sympathetic, 

 and the inferior, one on each side. The right lies in front of 

 the innominate artery, and joins the deep cardiac plexus. The 

 left, in front of the arch of the aorta, joins the superficial cardiac 

 plexus. 



