Emphysema ; Asthma 



197 



As contiguous cells coalesce, the intervening capillaries perforce 

 disappear, and the oxygenating area is diminished thus, the large- 

 chested man is actually short of breath. The right side of the heart is 

 engorged, its ventricle is hypertrophied (p. 175), tricuspid regurgitation 

 occurs (p. 172), and with it a systolic, venous pulse occurs in the neck. 

 The venae cavas are overloaded, the face being dusky and livid ; piles 

 may occur, and later on dropsy ; the liver becomes nutmeggy, and 

 the urine may be albuminous. But, though the right ventricle is much 

 hypertrophied, the impulse is imperceptible, and its sounds are not 

 increased, for the heart is ' smothered ' by the expanded lungs. 



Though the liver is depressed, it may not be conspicuous below the 

 ribs, for, the chest having been greatly enlarged from before backwards, 

 plenty of room is thus provided for it. 



Occasionally the enlargement of the lungs is such that their in- 

 flated borders overlap each other behind the sternum. Such lungs 

 when removed from the thorax are sure to retain the prints of the ribs. 



In extra-vesicular emphysema air may leak from the emphysematous 

 lung into the connective tissue of the chest and so find its way into 

 the subcutaneous tissue of neck and 

 trunk (general emphysema). On rare 

 occasions the parturient woman has, 

 in her violent straining, ruptured cer- 

 tain air-cells, and air having escaped 

 through the interlobular tissue has 

 found its way to the face and eyelids, 

 inability to see from between the lids 

 having suddenly supervened. 



Both in emphysema and pneumo- 

 thorax there is a deficiency of breath- 

 sounds, and there is also a hyper-reso- 

 nance on percussion ; there is, however, 

 no difficulty in distinguishing the con- 

 ditions, as emphysema affects both 

 sides of the chest, pneumothorax only 

 one bilateral pneumothorax being 

 incompatible with life. Indeed, when 

 both lungs are crippled by phthisis, and 

 ulceration of the wall of a vomica allows 

 air to escape into one pleura, death 

 may suddenly occur, the remains of the 

 other lung not sufficing for respiration. 



Contraction of the muscular tissue 



of the bronchi, from irritation of the p yo -pneumothorax. (DR. FENWICK.) 

 vagi, as in indigestion, causes spas- 

 modic asthma, which may also be produced by direct irritation, as in 

 the uraemia of Bright's disease. The nerve-irritation may also be 



