326 



HEAD AND NECK 



The vocal folds are the agents by means of which the voice 

 is produced. The ventricular folds are of little importance 

 in that respect ; indeed, they can be destroyed, in great part, 

 without any appreciable effect upon the voice. 



The rima glottidis is the elongated fissure by means of 

 which the middle compartment of the larynx communicates 

 with the lower subdivision. It is placed somewhat below 



the middle of the 



ligament ^ * B * 



which it constitutes 

 the narrowest part. 

 Anteriorly, it is the 

 interval between the 

 vocal folds ; pos- 

 teriorly, it is the in- 

 terval between the 

 bases and vocal 

 processes of the 

 arytaenoid cartilages 

 (Fig. 121). It is 

 composed, there- 

 fore, of two very 

 distinct parts (i) 

 a narrow, anterior 

 portion, between 

 the vocal folds, in- 

 volving less than 

 two - thirds of its 

 length, and called 

 the pars intermem- 

 branacea ; (2) a 

 broader, shorter 

 portion, between 

 the arytaenoid cartilages, termed the pars inter cartilagima. 

 The form of the rima glottidis undergoes frequent alterations 

 in the living person. During ordinary quiet respiration it 

 is lanceolate in outline, and the intermembranous part has 

 the form of an elongated triangle, with the base directed 

 backwards. When the rima glottidis is widely opened the 

 broadest part of the cleft lies between the extremities of the 

 vocal processes of the arytaenoid cartilages, and there each 

 side of the rima presents a marked angle. The two vocal 



Cartilage of epiglottis 

 Fatty pad 

 Thyreo-hyoid membrane 



Thyreoid cartilage 



Elevation produced by 

 , cuneiform cartilage 

 Ventricular fold 



Philtrum ventriculi 

 Elevation produced 

 by arytaenoid cartilage 

 Laryngeal ventricle 



Vocal fold 



M. arytaenoideus 



Processus vocalis 



_ Lamina of 

 cricoid cartilage 

 Arch of 

 cricoid cartilage 



FIG. 1 20. Median section through the Larynx, 

 to show the Side Wall of its Right Half. . 



