INFLAMMATION. 



175 



tes. Exudates may in jiart lie consumed as nutrition 1)v local 

 cells. 



e. Disposal of necrotic tissue. Necrotic tissue is disposed of 

 by sloughing, absorption, phagocytosis, or seipiestration. Small 

 areas of necrotic tissue are usually promptly absorbed or dis- 

 posed of by phagocytic action. Considerable time is usually re- 

 quired in disposing- of large areas or masses of necrotic tissue, 

 unless it is superficially located and separates from the surround- 

 ing tissue and sloughs. Subsurface necrotic tissue may be gradu- 

 ally liquefied and absor1)ed, discharged through a fistulous tract 

 (submaxillary abscess of Strangles), collected and carried out 

 by phagocytes, encapsulated, or sequestrated, and remain per- 

 manently in the tissue. Encapsulated necrotic tissue ma\- be- 

 come infiltrated with calcium salts. 



f. Regeneration of degenerated tissue and reiilaccment (jf 

 necrotic tissue. The regeneration of degenerated tissue consists 

 in replacing the injured or destroyed cell ijrotoplasm b\- normal 

 protoplasm. If mdy a few cells are destroyed the ailjacent cells 

 reproduce and thus renewal is usualK- ra|")id. Connecti\'e tissue 

 cells and surface epithelium are easily and efficienth- regenerated, 

 but cardiac muscle, ganglionic nerye and cartilage cells are 

 rarely perfectly regenerated. Large areas of necrotic tissue are 

 usualK' substituted In- fibrous tissue. This proliferated tissu-e is 

 termed granulation tissue in the beginning and cicatricial tissue 

 after it has become dense and more or less contracted. Granu- 

 lation tissue consists r)f capillary loops surrounded by masses 

 of cells. These cells are largely fibroblasts and pnicluce fibro- 

 connecti^-e tissue. .After the fibro-connecti\-e tissue has l^een 

 formed it contracts, thus Ijecoming cicatricial tissue. Cicatriza- 

 tion is of value in closing gaping \younds, but is iniuri(-)us when 

 it occurs in internal organs as the liyer, because the ]iressure 

 produces atrophy and oljstructs circulation. The capsule sur- 

 rounding pus cavities, after the purulent fluid has I)cen eyacuated, 

 becomes a granulating mend)rane which soon fills the gap with 

 fibrous connective tissue. Exuberant granulation results from 

 excessive multiplication of cells, undue extension of capillary 

 loops, and failure of contraction of the fibrous tissue. 



Tissue Proliferation. — The tissue proliferated in inflammatory 

 resolution takes the place of tissues that pre-existed and had be- 

 come necrotic, while that occurring in inflammation resulting 

 from long continued mild irritation is not a substitution but an 

 addition "to the tissue already existing. In this latter phase 

 tissue proliferation may begin in a very short time after the in- 

 flammation is established or it may not appear for two, three, 



