128 VliTl-.RlNARV PATllOLOGV. 



EMBOLISM. 



DEFINITION. 

 SOURCE OF EM BOLL 



Tliroinbic fniQDiciits. 



Cells, fat. leukemia, tniiinr. ele. 



Pai'asiles. 



Air. 

 LOCATION, ivhere vessels branch. 

 EFFECTS. 



limhijlism is a condtimi resulting from an obstruction of a 

 bldod vessel bv a foreign h<idy (enil)r)lus) tliat is suspended in 

 the blood and is too large to ])ass thrriugh tlie vessel. An embo- 

 lus is a foreign body in the blood such as air, sarcoma cells, 

 etc. 



Source of Emboli. — Thrdinbic froiiincut^. — iM-agments from 

 disintegrating thrombi Boat in the l/lmid until thcv arri^'e at 

 vessels that are too small tn allow tliem to pass and there becom- 

 ing impacted produce emlxilism. An entire thrombus ma}^ also 

 bcciime detached and float in the bl(ii)d stream as an embolus 

 which, when impacted, A\-ould jn-nduce endxilism. A thrombus in 

 an .arter\- usually extends back to, and sometimes hevond 

 the first branch, the ])riijection fre(|ucntl\' becoming loosened and 

 carried into the branch as an embolus. 



Ahiionmil cells. — Leukemia is frc(|ucnth- accompanied by 

 knd^emic infai'cts, a result of ])lugging of vessels by the enlarged 

 leucocytes or leukemic cells. ?\letastatic sarcduiata are the result 

 of sarci miati lus cells floating in the blond and becoming impacted 

 in small vessels where thev multiply, thus producing secondary 

 tumors. Fat cells are a frecpient cause nf endxilism especially 

 in the human, after a fractiu^e of a lung bone in which the blood 

 vessels are lacerated and fat cells from the marrow enter the 

 blciod stream. 



Parasifci. — Embolism may lie the result of animal parasites. 

 The Strong}dus armatus, in the lar\-al stage is found in the 

 blorid vessels of the horse and fre(|uentl\- produces aneurisms 

 of the anterior mesenteric arterw Here a thrombus forms, the 

 fragments of which passing rm as emboli thus produce obstruc- 

 tions in the intestinal vessels which ma_y result in thrombo- 

 embolic colic. 



I'cqckihlc inicroorriani.^iiis- mav cause embolism, thus bac- 

 teria in the blood are emboli. Pyemia result from metastases 

 of pA'ogenic organisms and pus. Apoplectic anthrax in sheep 

 may be the result of emboli of Bacilltis anthracis plugging the 

 cerebral capillaries thus producing embolism. 



.-/;V may act as an embolus and olistruct small vessels, or it 



