226 \■|■;TI■;Rl^'.\R^■ i>ATiK)L()GV. 



( )SSIFICATIOX. 



PIIYSJOLOGIC. 

 PATHOLOGIC. 

 ETIOLOGY. 



Inilalloii. 



IiiifTOl^cr iinlnlioii. 

 APPEARAXGli. 



ilacrosiopiL — Ossciuis mosses. 



Microscot^ic — Osseous plates. 

 TISSUE AEEECTEP. 



Muscle. 



Arteries. 



Tumors. 

 EFFECTS. 



( )ssificatinn, as in the furmation of lione, is a nurmal jirocess. 

 Tlie ]irocess consists in the formation of fibmns lamellae that 

 are later calcified. ( )sseous bodies are s()metimes formed in such 

 structures as the falx cerebri and tentorium cerebelli. These 

 osseous formations assume the shape of tlie oriijinal structures, 

 and are called osteophytes. 



Patholoe;"ic ossification consists in the formation of a bone 

 like substance in abnormal locations, as muscles, arteries, tum- 

 ors, etc. 



Etiology. — r)ssification probably results from chronic irrita- 

 tion, improj^er circulation, or impoverished nutrition. 



Appearance. — Macrascopic. — Ossified muscle appears as a 

 porous osseous mass. In an autopsy of a horse the fle.xor bra- 

 chii muscle, was found to be a porous osseus mass, and appeared 

 like cancillated bone. Aluscle ossification is usually des- 

 ignated myositis ossificans. An ossified falx cerebral or tentor- 

 ium cerebellar osteopliyte appears as irre,Siular l^on-s' masses. 



Microscopic. — The porous osseous tissue formed in pathologic 

 ossification is found on microscopic examination to consist of 

 osseous plates surrounding irregular cavities. 



Tissue affected. — Muscle, arteries, connective tissue and tum- 

 ors. 



Effects. — rissification occurs only when the normal struct- 

 ures have been praclicalh- destroyed. It represetits a condition 

 that is not reparable. 



For difterentiation of this condition and osteomata see discus- 

 sion of the latter. 



