CHAPTER III 



INFLAMMATION AND LEUCOCYTE RESPONSE 



Introduction. — lu regard to the phenomena of infection and 

 its sequelae the older clinicians carefully describe inflammation as 

 the reaction of the tissues to injury. Virchow and succeeding 

 pathologists have reported upon the microscopical changes which 

 occur. Experimental hematologists such as Ehrlich, Sabin, Doan 

 and Cunningham, Maximow, Downiey, Bunting, Pappenheim, and 

 others have introduced methods of staining, identifying and classi- 

 fying the various types of cells ol)served in the blood, inflammatory 

 exudates, and lesions and have attempted to determine their origin 

 (Plates I and II). Arneth, Schilling, and more recently Haden 

 have suggested that in acute infections the activity of the bone 

 marrow (Plate 1,1) is reflected by the relative number of young 

 forms of neutrophiles in the peripheral circulation. They believe 

 that in acute infections a prognosis can be based upon indices or 

 hemograms giving this information and accordingly suggest for- 

 mulae for such indices and liemograms. 



Acute Inflammation. (1) Lobar Pneumonia. In acute lobar 

 pneumonia, which is usually caused by the pneumococcus, there is 

 an acute inflammation of at least one lobe of tlie lungs accom- 

 panied by systemic disturbance. It is ushered in with a chill, 

 fever, leucocytosis, rapid pulse, and rapid respiration. Obviously 

 there is a disturbance of respiratory function. The inflammatory 

 process in the lung is characterized by several stages. 



Like all acute inflammatory processes the first stage is one of 

 liyperemia or increase in ])lood supply to the infected lobe. In 

 pneumonia this is called the stage of engorgement. During this 

 stage there results a change in permeability of the vessel walls, a 

 slowing down of the rate of blood flow and a margination of leuco- 

 cytes. This is ako common to all inflammatory processes. Leuco- 

 cytes are attracted to the infected lungs. Fluid, leucocytes, and 

 even some red cells pass through the vessel walls into the alveoli. 



Tlie second stage is ushered in by the consolidation of the lung 

 due to the clotting, so to speak, of the inflammatory exudate. Tliis 



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