734 



TSE NERVES. 



5. Inferior Lakyngeal Nerve (Kg. 362, 27, 28).— Also named the 

 recurrent, or tracheal recurrent, because of its disposition. It begins in the 

 thoracic cavity and ascends along the trachea to the larynx, all of whose 

 intrinsic muscles it animates, with the exception of the crico-thyroid. 



The two recurrent nerves 



Fig. 341. 



are not quite symmetrical 

 at their origin. That of the 

 right side is detached from 

 the pneumogastric below the 

 axillary artery, nearly at the 

 dorso-cervical arterial trunk. 

 It is immediately reflected 

 forward in embracing the 

 origin of that trunk, which 

 it crosses inwards to be 

 placed against the trachea, 

 in the middle of the prin- 

 cipal cardiac nerves, with 

 some of which it contracts 

 intimate adherences. 



On the left side, it is 

 only when the pneumogas- 

 tric nerve arrives near the 

 root of the lung that it 

 gives off its recurrent. To 

 be reflected forward, the 

 latter turns from left to 

 right behind the arch of 

 the aorta, and arrives be- 

 neath the inferior face of 

 the trachea, among the 

 cardiac nerves, with which 

 it communicates like the 

 right. 



The inferior laryngeal 

 nerves are in this way 

 mixed, at a greater or less 

 distance from their com- 

 mencement, with those sym- 

 pathetic nervous branches 

 which collectively constitute 

 the tracheal plexus. They 

 are soon disengaged, how- 

 ever, and leave the chest, 

 but always in proceeding 

 along the inferior face of 

 the trachea, then ascending 

 on its sides, below the ca- 

 rotid arteries, which they 

 gradually approach, and 



finally attain the larynx in penetrating beneath the crico-pharyngeal 



muscle. 



According to Goubaux, the left recurrent must be situated more super- 



DISTEIBUTIOS OF THE NERVES IN THE LARYNX OF THE 

 HOESE. 



a, Base of the tongue ; b, Epiglottis ; c, Arytenoid 

 muscles ; d, Section of the thyroid cartilage to show 

 the parts it covers ; e, Cricoid cartilage ; /, Trachea ; 

 g, ffisophagus ; h, Thyro-arytenoid muscle ; {, Lateral 

 crico-arytenoid muscle ; j, Posterior crico-arytenoid 

 muscle ; k, Arytenoid muscle. — 1, Superior laryngeal 

 nerve ; 2, Inferior laryngeal ; 3, Branches of the supe- 

 rior laryngeal passing to the epiglottis and tongue ; 4, 

 Branches of the superior laryngeal passing to the 

 cesophagus ; 5, Very fine multiple anastomoses between 

 the two laryngeals ; 6, Tracheal branches ; 7, Branch 

 to the posterior crico-arytenoid muscle ; a portion is 

 distributed, through the muscles, to the subjacent 

 mucous membrane ; 10, Branch passing to the arytenoid 

 muscle; 11, (Esophageal branch of the pharyngeal 

 nerve ; it sometimes comes from the external laryn- 

 geal. — From Toussaint's work. 



