CHAPTER VI. 



THE RESPIRATORY SYSTEM. 

 The Nose and its Associated Cavities. 



THE mucous membrane lining the nose under normal conditions cleanses from dust 

 the air which impinges upon and sweeps across it in respiration. It is in this way ex 

 posed to various deleterious agencies. It is subject also to such sudden changes of tern 

 perature as may involve great and abrupt alterations in the condition of its blood- 

 vessels. 



INFLAMMATION. (Rhinitis.) 



Acute Catarrhal Inflammation is common arid often associated with a 

 similar process in the pharynx and larynx. There is at first a hyperaemie 

 swelling followed by an increased pro- 

 duction of mucus and transudatiou of 

 serum from the blood-vessels ; emigration 

 of leucocytes and desquamation of epi- 

 thelium may follow. This and other in- 

 flammatory processes may extend to the 

 frontal sinuses and the antrum where the 

 exudates may collect (Fig. 258). As the 

 process resolves, the exudation ceases, 

 the epithelium regenerates, and the mucosa 

 is restored to its normal condition. 



Pseudomembranous Inflammation, either 

 simple or diphtheritic, may involve the 

 nasal cavities. Phlegmonous inflamma- 

 tion involving adjacent parts is of occa- 

 sional occurrence. Bacteria apparently 

 play an important part as excitants of 

 acute catarrhal and pseudomembranous 

 inflammation. ' 



Chronic Catarrhal Inflammation may follow the acute form, and is 

 marked by hyperplasia of the fibrous tissue in the submucosa, often fol- 

 lowed by atrophy of the mucosa. Ulceration of the mucosa may occur ; 

 the exiuiate may assume a fetid character. An hyperplasia of the mu- 

 cosa may lead to the formation of the so-called mucous polyps." These 

 often contain hyperplastic mucous glands and they are often oedematous. 



1 For a study of the bacteriology of nasal inflammation see Howard, Am. Jour. Med. 

 Sciences, vol. cxv., p. 520, 1898. See also for bacteria of the nose, Neumann, Zeits. f. 

 Hyg., etc., Bd. xl., p. 33. For a study of the lymph-vessels of the nose and pharynx 

 see Most, Arch. f. Anat. u. Phys., 1901, p. 75. 



3 For a summary of facts concerning the nature of the ordinary nasal polyps see 

 Wright, New York Med Record, January 26th, 1901, p, 132, bibliography. 



FIG. 258.-CATARRHAL INFLAMMATION OF 



THE Mucous MEMBRANE OF THE ANTRUM. 



Showing migration of leucocytes through 



the epithelium. 



