RETROCRKSSIVE TISSUE cnAN(;i';s. 



229 



incrustation of scales of lime and the framework of the lung mav 

 be infiltrated with small gritty calcareous masses. " ' 



Microscopic.—Thc calcareous material may be amorphous vr 

 crystalline and it may occur in the cells or between the cells. 

 Cellular calcareous infiltration normally occurs in the cells of 

 the pineal body and patholooically in kidney cells, nerve cells, 

 etc. The calcareous granules or crystals are usually stained 

 dark with hematoxylin and give the general impression that 

 chromatolysis (fragmentation of the nucleus) had occurred. 



Fig. 120 — .\tlieroTiiatous Degeneration. .Aorta. 



a. Calcarious duposit in the tunica media. 



Calcareous material infiltrated between the cells ma^■ lie amor- 

 phous or crystalline and assumes the same stains and appears 

 similar to the intracellular infiltrated lime salts. The calcareous 

 material is soluble in dilute acids, except calciuiu sulphate, with 

 more or less eft'ervescence. 



Tissue Affected. — Necrotic tissues are most suljject in cal- 

 careous infiltration. fSlood vessels, lung tissue, kidney tissue, 

 dense fibrous tissue, are also subject to calcareous infiltration. 



Effects. — Calcareous infiltration is a means of cnnxcrting 

 necrotic tissue into a noninjurious luass. Calcified tissue is prob- 

 ably never regenerated because calcareous deposits are not ab- 

 sorbed. 



