504 



THE RESPIRATORY SYSTEM. 



Chronic Phthisis, many phases of which have been elaborately described 

 as if they were the expression of independent processes. 



With our present knowledge of the nature and etiology of tuberculosis 

 it seems better to let the word phthisis fall into disuse as speedily as 

 possible and to consider under more exact and significant designations 

 such phases of pulmonary tuberculosis as the morphological characters 

 of the lesions justify. We shall review the lesions of pulmonary tuber- 

 culosis then under the following primary headings : 



1. Focal or miliary tuberculosis. 



2. Tuberculous broncho-pneumonia. 



3. Complex forms of nodular and diffuse tuberculosis lesions. 



4. The formation of cavities. 



5. Secondary lesions in pulmonary tuberculosis. 



6. Concurrent infection. 



FOCAL TUBERCULOSIS. (Miliary Tuberculosis.') 



Acute Miliary Tuberculosis. The rapid and widespread development 

 of miliary tubercles in the lungs is often a part of general tuberculosis, 

 although the lesion may be most extensive in the lungs. Both lungs are 

 apt to be involved, but the distribution, number, size, and character of 

 the miliary tubercles differ in different cases. The tubercles are found 

 in the parenchyma of the lung, in the connective tissue forming the 







FIG. 284. MILIARY TUBERCLE OF LCXG. 



This tubercle has replaced several air vesicles whose^walls are obliterated. In the centre is an area of 

 coagulation necrosis, outside of this is a zone of organized tubercle tissue ; the surrounding air vesicles 

 contain a cellular exudate. 



septa, along and in the walls of the bronchi and blood-vessels, and in the 



