RESPIRATORY APPARATUS. 125- 



lungs. These are rattling throat sounds, wheezing, groaning, 

 etc. Their appearance in the chest has no diagnostic signifi- 

 cance. 



An exaggerated vesicular murmur occurs: 



1. If the respirations are intensified, therefore in physio- 

 logical and pathological dyspnea. 



•?. If it is compensatory; that is, if one portion of the 

 lung is required to perform extra work for another portion 

 which is diseased and incapable of taking part in the respira- 

 tory act, [For instance, where one lung does the dutv of its 

 fellow which is diseased.] 



3. If a bronchitis is setting in, the lumen of the bronchi 

 being contracted by swelling of, or collections of exudate on, 

 the mucous membrane. The exaggerated vesicular murmur 

 in such cases is a symptom of great diagnostic importance. 



A diminished or feeble z'esicular murmur occurs: 



1. If the thoracic wall is thickened from fat accumula- 

 tions or disease : swelling, neo formations. 



2. If the air cannot enter the vesicles 

 in consequence of great swelling or plugging of the larger ■ 

 bronchi : severe bronchitis. 



3. If the exchange of gases in the lungs 

 is impaired: emphysema, beginning hepatization, and a 

 partial compression of the lungs by pleuritic exudate. 



Absence of the vesicular murmur, and no other sounds 

 present in the lung [i. e., total absence of any pulmonary 

 sound] occurs: 



1. If pleural exudates or tumors have displaced the lung 

 tissue : 



2. Rarely in severe vesicular pulmonary emphvsema, or a 

 complete occlusion of a bronchus preventing access of air into 

 a certain portion of the lung. 



Jerking, interrupted respiratory sounds are often produced 

 by animals voluntarily, from restlessness or fear. In such 

 cases it is heard in both lungs. Pathologically it is 



