GENERAL ARRANGEMENT OF THE PHONATING ORGANS 541 



with the motor organ, namely, with the larynx and its adjuncts as well 

 as with the nervous paths which connect this organ with the motor 

 area in the Rolandic area of the cerebral cortex. The function of the 

 psychic center for speech and the manner in which afferent impulses 

 are enabled to influence its action, will be discussed later on in connec- 

 tion with the function of the cerebrum and allied parts. 



General Structure of the Larynx. — This organ consists of a 

 framework of cartilages held together by ligaments and acted upon 



Fig. 266. Fig. 267. 



Fig. 266. — Laryngeal Cartilages and Ligaments, Anterior Surface. 



1, hyoid bone; 2, 2, 3, 3, greater and lesser cornua; 4, thyroid cartilage; 5, thyrohyoid 

 membrane; 6, thyrohyoid ligaments; 7, cartilaginous nodule; 8, cricoid cartilage; 9, 

 the cricothyroid membrane; 10, the cricothyroid ligaments. 11, trachea. (Sappey.) 



Fig. 267. — Laryngeal Cartilages and Ligaments, Posterior Surface. 



1, 1, thyroid cartilage; 2, cricoid cartilage; 3, 3, arytenoid cartilages; 3, 4, crico- 

 arytenoid articulations; 5, 5, cricothyroid articulations; 6, union of the cricoid cartilage 

 and of the trachea; 7, epiglottis; 8, ligament uniting it to the reentering angle of the 

 thyroid cartilage. (Sappey.) 



by a system. of extrinsic and intrinsic muscles. The following carti- 

 lages enter into its formation: 



Single cartilages Paired cartilages 



Thyroid Arytenoid 



Cricoid Cornicula laryngis 



Epiglottis Cuneiform 



But even in the case of the single cartilages, a certain tendency toward 

 bilateralism is unmistakable, because they are thickest and most 

 extensive at the sides of the larynx and are united in front by merely 

 a narrow bridge of connecting tissue. These cartilages are adjusted 

 upon the anterior extremity of the trachea in such a way that a rela- 

 tively large cavity is formed which is protected against the pharynx 

 by the epiglottis. Its pharyngeal aperture is triangular in shape, 

 its base being directed forward and its apex backward. 



