408 



HEAD AND NECK 



Epiglott 



superior aperture (aditus laryngis) of the larynx down to the 

 plicae ventriculares. In its lower part it exhibits a marked 

 lateral compression. Its width, therefore, diminishes from 

 above downwards, whilst owing to the obliquity of the aditus 

 the anterior wall is longer than the posterior. Anteriorly it 

 is bounded by the posterior surface of the epiglottis and the 

 thyreo-epiglottic ligament, both covered with mucous mem- 

 brane. This wall 

 descends obliquely 

 from above down- 

 wards and anteri- 

 orly, and becomes 

 narrower as it 

 approaches the 

 anterior ends of the 

 plicae ventriculares. 

 Each lateral wall 

 of the vestibule is 

 formed by the 

 medial surface of 

 the ary-epiglottic 

 fold. For the most 

 part it is smooth 

 and slightly con- 

 cave, but in its 

 posterior part the 

 mucous membrane 

 bulges medially in 

 the form of two 

 elongated vertical 

 elevations placed 

 one posterior to 

 the other. The 



anterior elevation is formed by the cuneiform cartilage and 

 a mass of glands associated with it, enclosed within the 

 ary-epiglottic fold ; the posterior elevation is due to the 

 anterior margin of the arytaenoid cartilage and the cor- 

 niculate cartilage. A shallow groove descends between these 

 rounded elevations and terminates below by running into the 

 interval between the ventricular and the vocal folds. The 

 posterior wall of the vestibule is narrow, and corresponds to the 

 interval between the upper parts of the two arytaenoid cartilages. 



Hyoid bone 



Ary- 

 epiglottic fold 



Tubercle of epiglottis 



Thyreoid cartilage 



Plica ventricul 

 Ventricle of larynx 



Plica vocalis 



Musculus vocalis- 



Cricoid cartilag 



FIG. 157. Frontal section through the Larynx 

 to show the Compartments. 



