Chap, viii.] THE PHARYNX. 133 



vertebra. The upper vertebrae can be examined, as 

 regards their anterior surface, from the mouth. When 

 the bones about the pharynx are diseased, the necrosed 

 parts may be discharged by that cavity. Thus por- 

 tions of the atlas and axis have been expelled by the 

 mouth, as have also been some fragments of compara- 

 tively lai'ge size thrown off by the occipital and 

 sphenoid bones. 



The mucous membrane of the pharynx is vascular, 

 and readily inflamed ; and such inflammations are 

 peculiarly dangerous, in that they may spread to the 

 lining membrane of the larynx. Much adenoid tissue 

 is distributed in the mucous membrane of the pharynx, 

 and it is this tissue that is the primary seat of inflam- 

 mation in scrofulous pharyngitis. A distinct collec- 

 tion of adenoid tissue stretches across the hinder wall 

 of the pharynx between the openings of the Eustachian 

 tubes. It is known as Luschka's tonsil, or the pharyn- 

 geal tonsil. This deposit of adenoid tissue may under- 

 go hypertrophic change and the condition known as 

 " adenoid vegetations " or " post-nasal growths " be 

 produced. These growths may cause deafness, and 

 may block the posterior nares. They need to be re- 

 moved by operation. The tissue immediately outside 

 the pharynx walls is lax, and favours the spread of 

 effusion. Thus, in acute inflammation of the pharynx 

 the effusion has been found to extend along the 

 oesophagus, reaching the posterior mediastinum, and 

 advancing even to the diaphragm. In the lax con- 

 nective tissue between the pharynx and the spine 

 abscess is nob infrequent, due, as a rule, to caries of 

 the vertebrae (post-pharyngeal abscess). In this con- 

 nective tissue, and opposite the axis, is also found a 

 lymphatic gland that receives lymphatics from the 

 nares. This gland may prove the seat of a suppura- 

 tion. Such collections may so push forward the pos- 

 terior pharyngeal wall as to depress the soft palate, 



