Iiifarcfioii. T47 



infiltrated with lucniorrliagic ci'lusiun. Ju larj^e infarcts the con- 

 gestive reflux of venous blood is often restricted to the periphery 

 of the area alone, the central portions remaining anaemic and hav- 

 ing therefore only a red areola. 



Infarcts as a rule are conical in shape, the apex of the cone 

 at the position of arterial occlusion, the expansion from this point 

 corresponding with the branching of the artery. From fusion of 

 closely situated infarcts or in those of flat organs like the wall of 

 the intestinal canal, the conical shape may be indefinite and the 

 outlines suggestive of a map. Hasmorrhagic as well as anaemic in- 

 farcts occasion destruction of the tissue, the circulation being en- 



&i^ ,^- 



•«• 





Fig. 14. 

 Conical liaemorrhagic infarct.s in a portion of the Ividney of a cow. 



tirely ended in the area involved ; the tissue with all the blood which 

 has engorged it being reduced to a mass of coagulated necrotic ma- 

 terial. Such an area excites an inflammation in the surrounding 

 tissue, to the formation of an actual inflammatory zone of demarca- 

 tion ; a wall of leucocytes collecting around the area of coagulated 

 material, fibroblastic and angioplastic cells from the surrounding 

 healthy structure penetrating the infarct, whether it be an.xmic or 

 hsemorrhagic, the blood and disintegrating tissue of the infarct 

 being removed by phagocytosis, and the site of the infarct being 

 eventually occupied by a mass of contracting connective tissue 

 (infarct scar). Such cicatrices are quite common in the kidneys 

 (cicatricial kidneys). When either an anremic or h?emorrhagic 

 infarct is related to some surface infected with bacteria these in- 



