PHARYNX 



379 



Posteriorly, the opening rapidly narrows, and finally ends in 

 the interval between the two arytaenoid cartilages. The 

 sides of the aperture are formed by two sharp and prominent 

 folds of mucous membrane, termed the ary-epiglottic folds, 

 which connect the lateral margins of the epiglottis with the 

 arytcenoid cartilages. Two small nodules of cartilage, in the 

 posterior part of each ary-epiglottic fold, give rise to two 

 rounded eminences, of which the anterior is the cuneiform 

 tubercle, and the posterior the corniculate tubercle, 



On either side of the lower part of the laryngeal open- 

 ing there is a small three -sided or pyramidal depression, 

 called the recessus piriformis. On the lateral side it is 



ilis 



rtilage 



Thyreo-hyoid membrane 



Plica vocali: 

 Processus vocalis 

 Arytamoid ca: 



Platysma 

 Posterior wall 

 of pharynx 

 Retropharyn 

 geal spaci 



Carotid sheath 



Sterno-hyoid 



Thyreo-hyoid 



Thyreoid cartilage 

 mo-hyoid 



Recessus piriformis 

 Superior thyreoid 

 Descendens 

 hypoglossi 

 Common carotid 

 Internal jugular 



Vagus 



Scalenus anterior 



Longus colli 



Vertebral artery 



Sympathetic trunk 



FIG. 151. Transverse section through the Neck at the level of upper 

 part of the Thyreoid Cartilage. 



bounded by the posterior part of the lamina of the thyreoid 

 cartilage and the thyreo-hyoid membrane ; on the medial side 

 by the arytaenoid cartilage and the ary-epiglottic fold ; whilst its 

 posterior wall is formed by the posterior wall of the pharynx, 

 when this is in place. The recessus piriformis presents a 

 wide entrance, which looks upwards ; but it rapidly narrows 

 towards the bottom (Figs. 150 and 151); and it is important to 

 the surgeon because in this little pocket foreign bodies intro- 

 duced into the pharynx are liable to be caught. 



Below the opening of the larynx, the anterior and posterior 

 walls of the pharynx are always closely applied to each other, 

 except during the passage of food. 



The asophageal opening is placed opposite the lower border 



