VOICE ANATOMY OF THE VOCAL APPARATUS. 455 



and its primary dependencies, which are immediately concerned in the 

 production of voice, will alone engage us at present. 



The larynx is situate at the anterior part of the neck, and forms the 

 projection so perceptible in that of the adult male, called pomumAdami. 

 An attentive examination of the various parts which compose it, so far 

 as they concern its physiological relations, will 

 be necessary. This will exhibit the imperfect Fi - 194 - 



knowledge of several writers on the voice, and 

 the false and insufficient views that have been 

 entertained on the subject. 



If we look along the larynx from the trachea 

 of which it is a continuation, we find that the tube 

 becomes gradually narrower from side to side ; 

 and, at length, presents an oblong cleft, called 

 glottis, the sides of which are the essential organ 

 of voice. 



The larynx is composed of four cartilages 

 the cricoid, thyroid, and two arytenoid. The 

 cricoid is the lowest of these, and is the inferior 

 part of the organ ; that by which it joins the 

 trachea. It is shaped like a ring, whence its 

 name, but is much deeper behind than before. 

 The thyroid is situate above the cricoid, with ^terai View of the Larynx. 

 which it is articulated in a movable manner by ^*$^ "3 . 



. 

 means of its inferior cornua. In this way, the majus of thyroid cartilage. 4. 



. _. . ., fi.vsT Its angle and side. 5. Cornu 



lower front margin or the thyroid, which is com- minus. 6. Lateral portion of 

 monly separated by a short space from the upper $&?***' 7 ' 

 margin of the cricoid, may be made to approach 



to or recede from it ; as may be ascertained by placing the finger 

 against the small depression felt externally, and observing its change 

 of size when various tones are sounded. It will be observed, that the 

 higher the tone the more the cartilages approximate, and that they 

 separate in proportion to the depth of the tone. A ligament unites 

 these cartilages the crico -thyroid, which can be traced, although in 

 a very thinned condition, over the whole of the periphery of the ventri- 

 cle of the larynx, even as far as the pedicle of the epiglottis. This 

 membrane is composed of the yellow elastic tissue tissu jaune, and, 

 according to Dr. Leidy, 1 it presents, under the microscope, a good 

 example of that substance, which enabled him to detect its presence in 

 the ventricles of the larynx. 



The thyroid is the large cartilage that occupies the anterior, promi- 

 nent, and lateral part of the larynx. The arytenoid cartilages are two 

 in number. They are much smaller than the others, and are articu- 

 lated with the posterior part of the cricoid in a movable manner. 

 Around this articulation is a synovial capsule. Before it is the thyro- 

 arytenoid ligament; and, behind, a strong, ligamentous fascia, called, by 

 M. Magendie, 2 from its attachments crico-arytenoid. Three fibro-car- 



1 Amer. Journ.of the Medical Sciences, July, 1846, p. 142. 

 * Precis Elementaire, i. 235. 



