THE RESPIRATORY SYSTEM. 



495 



Broncho-Pneumonia. Lobular Pneumonia with Inflammation of the 

 Smaller Bronchi. 



This most important type of lobular pneumonia frequently develops 

 in connection with and as an extension of that form of inflammation of 

 the smaller bronchi commonly called "capillary bronchitis." At first 

 dark red in color, the lobular areas of consolidation in broncho-pneu- 

 monia become more gray at the centre through degeneration of the ex- 

 udate, while the advance of the process in the periphery is marked by 

 a less solid, redder zone. On section of the fresh lung these areas (Fig. 

 275) usually project somewhat above the general surface and at their cen- 



FIG. 275. BRONCHO-PNEUMONIA IN AN ADULT. 



Showinp several areas of consolidation with the central bronchus filled with exudate stained dark in the 

 section from which the photograph was made. 



tres the involved bronchi may appear as lighter spots, from which pus 

 may exude or be easily pressed out. Such areas may coalesce, forming 

 larger consolidations. The exudate which more or less completely fills 

 the air spaces (Fig. 276) consists of serum, old and new-formed epithe- 

 lial cells from the walls of the air spaces, red blood cells, and often fibrin 

 and polymorphouuclear leucocytes (Fig. 277) with various forms of 

 micro-organisms. As a rule, however, fibrin and leucocytes are not as 

 abundant as in the exudate of lobar pneumonia. Mucus and bronchial 

 epithelium may be aspirated into the air spaces and mingled with the 

 exudates. 



Broncho-pneumonia involves a direct extension of the inflammatory 

 process from the bronchi to the contiguous lung tissue, so that there is 

 both an interstitial and exudative pneumonia about the bronchial tubes, 

 the whole forming the lobular areas of consolidation (Fig. 278). This 



