ANTERIOR ASPECT OF HEAD AND NECK. 



Pharynx. This expanded upper part of the alimentary 

 canal lies behind and communicates with the nose, mouth, 

 and larynx. It extends from the base of the skull to the sixth 

 cervical vertebra, where, at its narrowest part, it opens into 

 the O3sophagus; it is widest above (lateral recesses). The soft 

 palate divides it into the naso-pharynx above and the phar- 

 ynx proper below. The latter is divided into the oral pharynx, 

 lying behind the mouth and tongue; and the laryngeal phar- 

 ynx, lying behind the larynx. Loose areolar tissue (retro- 

 pharyngeal space) separates it from the prevertebral muscles 

 and fascia. [1029] 



Naso-pharynx. The posterior wall inclines upward and for- 

 ward (vault of the pharynx) to the anterior wall and presents 

 on its upper part, especially in early life, a mass of lymphoid 

 tissue (pharyngeal tonsil). On each lateral wall, one-third to 

 one-half an inch behind the posterior end of the inferior tur- 

 binated bone, and just above the level of the hard palate, is the 

 orifice of the Eustachian tube. This is bounded above and 

 behind by a ridge (Eustachian cushion), caused by the pro- 

 jection of the cartilage. Just behind this is a vertical slit-like 

 depression leading into a pouch (lateral recess, or fossa of 

 Rosenmuller) which extends outward over the Superior con- 

 strictor. [1032] 



Oral Pharynx. On each lateral wall the triangular interval 

 between the palatine arches and tongue is filled by the tonsil, 

 except at the upper (supratonsillar fossa) part. The orifice 

 (pharyngeal isthmus) between the oral pharynx and naso- 

 pharynx is oblique and triangular. The tonsil is an oval mass 

 of lymphoid tissue lying just above and in front of the angle 

 of the lower jaw. Laryngeal pharynx. A deep depression (sinus 

 pyriformis) lies on the anterior wall on each side of the laryn- 

 geal orifice, between the aryteno-epiglottic fold and ala of the 

 thyroid cartilage. [1034, 1036] 



(Esophagus. This muscular tube leads from the pharynx 

 to the stomach. It descends on the Longus colli and spine, 



[87] 



