304 CLINICAL APPLIED ANATOMY. 



explains the ready manner in which a sharp pointed instrument 

 introduced into the nostril may pass through the thin bone 

 forming the base of the skull in this region, and carry with it 

 septic material. 



Foreign Bodies in the Nostril. The difficulty of extracting 

 foreign bodies introduced into the nose arises from the follow- 

 ing anatomical facts : First, the irregularity of the walls of 

 the cavity ; secondly, its many recesses ; and thirdly, the swelling 

 of its mucous membrane as a result of the irritation and inflam- 

 mation produced by the body. For these reasons it is sometimes 

 more easy to push the imprisoned substance backwards into the 

 pharynx than to draw it forwards through the anterior nares. 



Polypi. The ordinary mucous polypi, or oedematous fibromata, 

 are usually the result of chronic inflammatory changes in the 

 mucous membrane of the ethmoidal region, and spring from 

 that portion of the membrane over the superior and middle 

 turbinate bones. Their presence tends to block the nasal cavity, 

 and they enlarge in the line of least resistance that is, down- 

 wards and forwards until they may even protrude through the 

 anterior nares. 



Septal Deviations. The bony and cartilaginous septum of the 

 nose is hardly if ever absolutely in the middle line, but it is only 

 when the degree of divergence from the perpendicular plane is so 

 great as to cause a considerably increased space in one nasal 

 cavity at the expense of the other that any real significance in 

 the condition arises. The obstruction to the passage of air on the 

 side to which the septum is deviated may be so great that it is 

 well nigh impossible to pass a probe along it, and hence an 

 operation becomes necessary. 



Adenoid Growths of the Naso-pharynx. The uppermost part 

 of the ring of adenoid tissue about the naso-pharynx and the 

 fauces is very frequently the site of hypertrophy, in the form of 

 pedunculated masses. These constitute the so-called " adenoid 

 growths." The pharyngeal tonsil, situated in the mucous 

 membrane forming the roof of the naso-pharynx between the 

 two Eustachian orifices, is not infrequently chronically enlarged 



