NORMAL ANATOMY OF THE LARYNX. 



100 



LARYNX. Syn.Gr.?u*(;<y|,fromXa^'y'yia> 

 (clamo); Fr. Larynx ; Germ. KehlkopJ ; Ital. 

 Laringe. The larynx is a complex piece of 

 mechanism resembling a kind of box, (piris 

 cava,) composed of an assemblage of carti- 

 lages, the density and elasticity of which serve 

 to protect its more delicate tissues, and to 

 allow the free transmission of air for respira- 

 tion. It is also exquisitely adapted for the 

 production of voice. 



The larynx is situated in the mesial line, 

 and opens superiorly into the pharynx, and 

 inferiorly into the trachea. It occupies the 

 anterior superior part of the neck, immediately 

 below the os hyoides, and before the pharynx, 

 which lies between it and the vertebral column. 

 In front it is very superficial, being covered 

 only by the sub-hyoidean muscles, and the 

 common integuments. 



It admits of various kinds of motion : 1, 

 those of elevation and depression parallel to 

 the long axis of the body; 2, those complex 

 movements within it which take place during 

 respiration and the production of vocal sounds. 



The larynx considered with reference to the 

 trachea, presents an enlargement denominated 



Fig. 18. 



the cnput asperse asteria, or the head of the 

 trachea. The absolute volume of the larynx 

 varies with the age and sex of the individual : 

 its magnitude is much more considerable in 

 men than in women ; in the former it acquires 

 an extraordinary developement at the age of 

 puberty. In eunuchs, however, this enlarge- 

 ment does not take place. 



The larynx does not represent any regular 

 geometrical figure; it may be denned as an 

 irregular, inverted, truncated cone, whose sec- 

 tions at the apex and base are elliptical, but 

 approaching nearly to a circle at its junction 

 with the trachea. 



This organ is perfectly symmetrical, which, 

 however, applies to one of its sections only, 

 viz. that of its mesial plane, or axis major ; 

 consequently, all the others must be unsym- 

 metrical : the section made at right angles to 

 it, or in its axis minor, gives the relative situa- 

 tion of its internal mechanism, as mjigs. 18 

 and 19, which should be carefully studied, with 

 reference to the physiology of this organ. 



fi'g.19. 



The anterior transverse section of the larynx and 

 trachea, a, the epiglottis ; b, b, the horns of the 

 os hyoides ; c, c, the inferior thyro-arytenoid liga- 

 ments (chorda: vocales) ; d, d, the thyro-arytenoid 

 muscles ; e, e, section of the thyroid cartilage ; 

 f, f, the superior boundaries of the ventricles ; g, g, 

 'section of the cricoid ; h, the trachea ; I, I, the 

 ventricles. 



The posterior view. The letters c, d, e, g, h, re- 

 present corresponding sections of the same parts ; 

 b, b, the arytenoid cartilages invested by mucous 

 membrane ; n, the pharynx laid open. 



The larynx is composed of several structures, 

 which may be classed as follows : 1, the car- 

 tilages ; 2, the ligaments ; 3, the muscles ; 

 4, the mucous membrane ; 5, the mucous 

 glands ; 6, the arteries and veins ; and, 

 lastly, the nerves. 



The cartilages of the larynx are nine in 



