104 



NORMAL ANATOMY OF THE LARYNX. 



articulation. The thyroid cartilage is united 

 to the os hyoides by three ligaments : the mid- 

 dle and two lateral. 1st. The ligamentum 

 thyro-hyoideum medium is a lax yellow tissue 

 arising from the superior margin of the thyroid, 

 and inserted into the inner margin of the os 

 hyoides : it is thicker and denser at its middle 

 part ; its lateral borders are involved with the 

 surrounding cellular membrane. The anterior 

 surface in its middle is situated immediately 

 under the integuments, having its sides co- 

 vered by the thyro-hyoidei muscles, (g, fig. 25) 

 and its posterior surface corresponding with the 

 form of the epiglottis. 2d. The ligamenta 

 hyo-thyroidea lateralia are small round liga- 

 ments on each side of the larynx, connecting 

 the tubercles of the great horns of the os hy- 

 oides with the extremities of the superior cor- 

 nua of the thyroid cartilage (c c. Jig. 24). In 

 the substance of these ligaments there are often 

 found small osseous or cartilaginous bodies. 

 The articulations of the thyroid cartilage 



Fig. 24. 



A mesial section of the larynx, from Lauth. The 

 mucous membrane and muscles are removed to expose 

 the elastic ligaments. 



a, the epiglottis; b, the hyo-epiglottic ligaments; 

 c c, the lateral thyro-hyoid ligaments ; e, a portion 

 of the glosso-epiglottic ligament ; f, the crico-thy- 

 roid ligament ; g i, the junction of the crico-thy- 

 roid, and lateral crico-thyroid ligament ; ri , the 

 attachment of the lateral crico-thyroid ligaments 

 to the base of the arytenoid cartilage ; n, the elas- 

 tic ligament lining the bottom of the ventricles ; o, 

 the superior inner margin of the cricoid cartilage ; 

 the lateral ligamentous connection with the inferior 

 vocal cord ; /, the superior vocal cord ; the right 

 arytenoid cartilage. 



with the os hyoides are furnished with syno- 

 vial membranes. 



The ligaments of the epiglottis. The epi- 

 glottis gives attachment to three ligaments, 

 which contribute to its elasticity and the stabi- 

 lity of its position. 



1. The ligamentum thyro-epiglottideum arises 

 from the mesial line below the notch of the 

 superior angle of the thyroid, and is inserted 

 into the base of the epiglottis. It binds the 

 epiglottis to the thyroid cartilage. 2d. The 

 ligamentum hyo-epiglottideum arises from the 

 inner surface of the base of the os hyoides; its 

 fibres passing horizontally are inserted into 

 the anterior surface of the epiglottis ; its action 

 tends to keep the position of the epiglottis per- 

 manently vertical. 3d. The ligamentum glosso- 

 epigluttideum arises from the base of the 

 tongue ; it lies in the median mucous folds be- 

 tween the tongue and epiglottis, and is inserted 

 into the anterior surface of the epiglottis im- 

 mediately above the ligamentum hyo-epiglot- 

 tideum. Its action is nearly the same as that 

 of the last-named ligament, but it is also con- 

 nected with the motions of the base of the 

 tongue. 



The tracheo-cricoidean articulation. The 

 lower margin of the cricoid cartilage is arti- 

 culated with the first ring of the trachea by a 

 series of the same ligamentous fibres which 

 connect the rings of the trachea with each other. 

 At the anterior mesial base of the cricoid there 

 are found additional ligamentous fibres. The 

 elastic tissue which connects the larynx with 

 the trachea permits considerable freedom in the 

 multiplied movements of the neck without im- 

 peding the regular transmission of the atmos- 

 phere. In these movements the first ring of 

 the trachea passes within the inferior margin of 

 the cricoid cartilage. 



The intrinsic articulations of the larynx are, 

 1st, the crico-thyroid ; 2d, the crico-arytenoid. 

 Besides these may be included the articulation 

 of the arytenoid with the cartilages of Santorini. 

 The cuneiform cartilages are generally unarticu- 

 lated in man. 



The crico-thyroid articulation. The inferior 

 cornua of the thyroid are curved forwards and 

 inwards. Their extremities present oblique 

 planes directed inwards and downwards, which 

 are firmly attached by a capsular ligament to 

 the oblique discs on the sides of the cricoid, 

 directed upwards and outwards. 



The ligament of this joint is of an orbicular 

 form, radiating in oblique fasciculi, the pos- 

 terior fibres of which extend nearly to the crico- 

 arytenoid articulation. 



The crico-thyroid ligament. Syn. Pyrami- 

 dal, or conoid ligament. Lat. Ligamentum 

 crico-tliyroidenm. Fr. Membrane, ou liga- 

 ment thijro-crico'idien moyen. The crico- 

 thyroid ligament is a very thick, strong, 

 yellow elastic ligament, arising from the 

 mesial line of the inferior margin of the 

 thyroid ; it then crosses the crico-thyroid 

 space, and is inserted into the superior mar- 

 gin of the cricoid. This ligament supports 

 the anterior part of the cricoid cartilage, and 



