SECTION III. 



RESPIRATORY APPARATUS, 



CHAPTER I. 



EXAMINATION OF THE RESPIRATORY APPARATUS, 



From the clinical standpoint a study of the respiratory apparatus 

 implies the examination of the nostrils, nasal cavities, frontal and 

 maxillary sinuses, larynx, trachea, and, for the purpose of ascertain- 

 ing the condition of the lungs and pleura, of the chest. 



Nasal cavities. Examination of the external portion of the nasal 

 cavities is extremely simple. The observer notes the degree to which 

 the orifices are dilated, the frequency of the respiratory movements 

 and the condition of the muzzle. He may find various eruptions, 

 crusts due to discharge, etc., and will remark any peculiarities pre- 

 sented by these. The depths of the nasal cavities can only be examined 

 through the nostrils to a very limited extent; but the condition of the 

 pituitary mucous membrane, its degree of vascularity, and the exist- 

 ence of ulcerations or of vegetations can be observed. 



Digital examination is sometimes useful in discovering the condition 

 of the lower portions of the turbinated bones. The electric light does 

 not greatly assist the observer, on account of the narrowness of the 

 air passages. On the other hand, examination of the face, and pal- 

 pation and percussion over the region of the frontal sinuses is of 

 considerable value. By inspection, one discovers deformity caused by 

 tumours, by ossific inflammation, or other lesions ; and detection is 

 rendered easier by the fact that deformities are usually asymmetrical, 

 only occurring on one side. 



Palpation reveals the degree of resistance and flexibility of the 

 external bony wall as well as the condition of the subcutaneous 

 tissues. 



Percussion sometimes discloses absolute dulness, due to tumours of 

 the mucous membrane, of the turbinated bones, or of the bones of 

 the face. 



The pharyngeal portion of the nasal cavities is difficult to reach, 



