1264 



A MANUAL OF ANATOMY 



Inferior Constrictor — Origin. — (i) The side of the cricoid cartilage 

 at its posterior part; (2) the inferior cornu and the obHque hne of 

 the ala of the thyroid cartilage; and (3) the upper border of the 

 ala behind the superior tubercle. 



Insertion. — The median raphe on the posterior wall of the 

 pharynx, Where it meets its fellow of the opposite side. 



The lower fibres of the muscle are horizontal, but the upper fibres 

 pass upwards and backwards more and more obliquely, and the 

 highest fibres of the two muscles meet in the raphe to form a peak, 

 which is about an inch below the basilar process of the occipital 

 bone. The lower border of the muscle overlaps the upper end of 



Sinus of Morgagni 



Superior Constrictor . . 

 Muscle 



Middle Constrictor 

 Muscle 



External Pterygoid Muscle 

 Styloid Process 



-C jndyle of 

 Mandible 



7...«,Spheno-mandibu- 

 lar Ligament 

 - Ramus of Mandible 



«,Stylo-phar. Muse. 



Stylo-hyoid Lig. 

 .^.Internal Pterygoid 

 Muscle 



Great Cornu of 



Hyoid Bone 

 Angle of Mandible 

 „. Median Raph^ of 

 Pharynx 



Inferior Constrictor Muscle- 



CEsophagus 



Fig. 519. — The Posterior Wall of the Pharynx and Adjacent 

 Structures. 



the oesophagus, and, to a hmited extent, some of the fibres are 

 continuous With the oesophageal muscular fibres. The recurrent 

 lar5mgeal nerve and inferior laryngeal artery pass upwards beneath 

 the lower border behind the crico-thjnroid joint. The upper border, 

 Which is very oblique, overlaps the lower portion of the middle 

 constrictor, and the internal laryngeal nerve and the superior 

 laryngeal artery, on their way to pierce the thyro-hyoid membrane, 

 pass between the two muscles anteriorly. 



Middle Constrictor — Origin. — (i) The upper surface of the great 

 cornu of the hyoid bone over its entire length, {2) the small cornu, 

 and (3) the hyoid extremity of the stylo-hyoid hgament. 



