138 Pharynx 



attached to fixed points. The fixed points by which the front of the 

 pharynx is held wide open are the internal pterygoid plates and the 

 halves of the lower jaw ; the cornua of the hyoid bone and the alae of 

 the thyroid ; and the sides of the cricoid cartilage. 



Ifot pharyngeal aponeurosis is a strong layer between the muscular 

 and mucous coats, which fills in the vacancy at the sinus of Morgagni; 

 it is connected with the occipital and petrous bones, and blends pos- 

 teriorly with the median raphe. 



The mucous membrane is continuous with that of the nares, 

 mouth, tympanum, and larynx. It contains many racemose glands, 

 and a large amount of lymphoid tissue packed around follicular re- 

 cesses. A mass of this tissue extending across the back of the pharynx, 

 between the Eustachian tubes, constitutes the so-called pharyngeal 

 tonsil. 



The epithelium of the respiratory part of the pharynx, that is, down 

 to the level of the floor of the nares, is columnar ciliated, but in the 

 rest of its extent it is squamous. 



The pharyngeal bursa is a recess in the posterior part of the mucous 

 membrane which may reach up to the pharyngeal tubercle. Con- 

 stantly present in infancy, it generally disappears with growth. 



Supply. The arteries are derived from the ascending pharyngeal 

 of the external carotid, and the ascending palatine and tonsillar of the 

 facial. The internal maxillary and lingual arteries may also supply 

 small branches. The veins are tributaries of the internal jugular. The 

 lymphatics pass to the glandular concatenate, and, quickly conveying 

 septic matter from the surface of the pharynx, are a constant source 

 of anxiety to the cervical glands. Some of the lymphatics of the 

 pharynx also end in glands in front of the cervical vertebra?, which, 

 becoming enlarged, may even be felt through the back of the pharynx, 

 and which may be the starting-point of post-pharyngeal abscess, 

 especially in young children. 



The pharyngeal plexus of nerves, from which the muscular and 

 mucous coats and the blood-vessels are supplied, is formed by branches 

 of the pneumogastric, superior laryngeal, glosso-pharyngeal, and 

 sympathetic. It is placed chiefly upon the middle constrictor. 



A pharyngeal polypus may spring from the base of the skull, and, 

 dragging upon its stalk, may hang like a pear behind the soft palate, 

 pushing it forwards and obstructing deglutition as well as respiration. 

 It may be removed by a wire snare passed along the floor of the nares, 

 and guided by the finger in the mouth beneath and around the 

 pedunculated mass. 



The stylo-pharyngcus arises from the base of the styloid process 

 and runs downwards and forwards between the external and internal 

 carotids, with the stylo-glossus and the glosso-pharyngeal nerve, and, 

 passing between the superior and middle constrictors, is inserted into 

 the sides of the wall of the pharynx and into the posterior border of 



