NORMAL ANATOMY OF THE LARYNX. 



102 



Jig. 21): the angle of union becomes more acute 

 as it approaches towards d. The prominence 

 of this angle on the mesial line constitutes 

 what is called the pomum Adami, which is 

 more developed in the male than in the female 

 sex, and becomes more conspicuous after the 

 age of puberty; it maybe readily felt in the 

 living subject. On the four posterior angles 

 of the thyroid are situated four cornua, or 

 horns ; two superior, 6, b, and two inferior, 

 c c, (fig- 21); they appear mere prolong- 

 ations of the posterior margins ; the superior 

 being longer than the inferior are called the 

 great horns; they are articulated to the os 

 hyoides by ligaments, which allow a motion 

 for the approximation and recession of the la- 

 rynx to and from the os hyoides. The inferior 

 horns are shorter, curved forwards, and arti- 

 culated at their extremities to the cricoid by 

 oblique planes, directed forwards and inwards. 

 On each wing of the thyroid there are two 

 tubercles, one on the superior, and the other on 

 the inferior margin (g, g, and h, h,fig- 21). 

 The superior tubercles are the largest. A small 

 ridge passes obliquely across the external sur- 

 face of the wings from g to h, extending from 

 the base of one tubercle to the other, dividing 

 each wing into two unequal segments, of which 

 three-fourths are anterior and superior, and 

 one-fourth posterior and inferior to the ridge. 

 The anterior margin of the ridge gives attach- 

 ment to the hyo-thyroid, and lies under the 

 sterno-hyoid muscles, and the posterior to the 

 inferior constrictor of the pharynx and sterno- 

 thyroid muscles. 



The posterior or hollow surface of the angle 

 formed by the junction of the alse of the thy- 

 roid gives attachment on each side of the me- 

 sial line to the thyro-arytenoid ligaments 

 (chordtz vocales) and muscles. The wings 

 are concave internally for the lodgement of the 

 thyro-arytenoidei and crico-arytenoidei laterales 

 muscles, and give attachment at their poste- 

 rior margins to the membrane of the pharynx. 



The superior margin of each wing is curved 

 in the line i, a, i, (Jig- 21,) and gives at- 

 tachment in its whole length to the thyro- 

 hyoid membrane : it is deeply notched at a, 

 immediately above the pomum Adami. It is 

 less deep, and more broad and round in 

 women than in men. 



Near the superior tubercles there is a notch, 

 sometimes a foramen for the transmission of 

 the superior laryngeal nerve. The inferior 

 margin of the thyroid is nearly horizontal, and 

 is shorter than the superior : there is a slight 

 prominence at a, (Jig. 21,) to which is attached 

 the crico-thyroid ligament. Between the in- 

 ferior tubercles at h, h, (Jig- 21,) and the in- 

 ferior cornua, the lower margin is arched rather 

 deeply. The posterior surface and margin of 

 the wings of the thyroid are ridged, and give 

 attachment to several muscles ; it rests against 

 the vertebral column, which forms a base to 

 the arc of the thyroid, and protects the internal 

 structure of the larynx. 



The an/tenaid cartilages. Syn. : Gr. 

 at>vrc(.ti/rjti$n<;, Galen ; Lat. Cartilagines ary- 



tenoidees ; Fr. Cartilages aryteno'ides ; Germ. 

 Giessbeckenknorpel. The arytenoid cartilages 

 are two very irregularly formed bodies, situated 

 on the articulating surface of the posterior, 

 inner, and upper margin of the cricoid, (b, 6, 

 Jig. 20,) in such a manner as to resemble the 

 mouth of an ewer ; hence their name. They 

 may be considered of a triangular or pyramidal 

 figure, having their bases spread out, (a and a, 

 Jig. 22,) and presenting surfaces for the attach- 

 ment of ligaments and the action of muscles. 

 We observe, 1, on their posterior aspect, 

 triangular concave surfaces, between f and e, 

 (fig. 22,) occupied by the oblique and trans- 

 verse arytenoid muscles. 2. Anteriorly, con- 

 vex, triangular surfaces, d, 6, (Jig- 22,) with 



Fig. 22. 



A fide view of the arytenoid cartilages, a, the 

 base and position of the crico-arytenoid articulating 

 grooves ; b, e, the posterior concave surface ; c, the 

 lateral prominence ; /, the corniculum laryngis ; 

 g, the vertical portion of the cuneiform cartilage. 



ridges, (b, fig. 27,) for the attachment of 

 the superior thyro-arytenoid ligaments. 3. La- 

 terally, cavities for the insertion of the thyro- 

 arytenoid muscles, and lodgment of the cunei- 

 form cartilages, (g,Jig- 22). 4. Internally, 

 surfaces reciprocally parallel, lined with mu- 

 cous membrane, which permit their close ap- 

 proximation. 5. Bases, on which are oblique, 

 curved, oval grooves, a and a, (Jig. 22,) cor- 

 responding to the articulating surfaces of the 

 cricoid ; there are also on each of these bases 

 two prominences, one lateral, (c, Jig. 22,) 

 which gives attachment (I, Jig. 27,) to the 

 crico-arytenoideus lateralis and posticus mus- 

 cles ; the other anterior, giving attachment 

 (V, fig. 29) to the inferior thyro-arytenoid 

 ligament. The latter prominence projects over 

 the vocal tube one-fifth of an inch in the male, 

 and one-seventh in the female. On the sum- 

 mit of the vertical prominences (J\J\fig- 22) 

 is situated a small appendage called corniculum 

 laryngis. The arytenoid cartilages have ex- 

 tensive freedom of motion, consisting of a rota- 

 tory, round the articulating axis of the cricoid, 

 O, P (fig. 30); and a sliding motion, trans- 

 verse to their axis of articulation about the 

 point B (fig. 30). 



The cornicula laryngis. Syn. Capitula San- 

 torini ; tubercles of Santorini ; cartilagines 

 comic ulis ; Santorinischer Knorpel, Germ. 

 These are two very small cartilaginous bodies 

 first described by Santorini, from whom they de- 

 rive their name. Their figure is nearly triangular 

 with a flat smooth surface at their bases, arti- 

 culated with some freedom of motion to the 

 apices of the arytenoid cartilages. They 



