Def.:Thrombosis is theformation of a bloodclot inside a bloodvessel or the heart,which can partially orcompletely obstructthe flow of blood. Theblood clot itself isreferred to as aTHROMBUS.
Coagulation: In medicine, the clotting of blood. The processby which the blood clots to form solid masses, orclots.# More than 30 types of cells and substances inblood affect clotting. The process is initiated byblood Platelets. Platelets produce a substancethat combines with calcium ions in the blood toform thromboplastin, which in turn converts theProtein Prethrompin into Thrombin in acomplex series of reactions. Thrombin, aproteolytic enzyme, converts Fibrinogen, aprotein substance, into fibrin, an insolubleprotein that forms an intricate network ofminute threadlike structures called fibrils andcauses the blood plasma to gel. The blood cellsand plasma are enmeshed in the network offibrils to form the clot.
Causes: The composition of the blood (hypercoagulability or thrombophilia) Quality of the vessel wall (endothelial cell injury) Nature of the blood flow (stasis, turbulence)
Classification: Venous thrombosis: Deep vein thrombosis
• Portal vein thrombosis (affecting the hepatic portal vein ) portal hypertension & blood supply to the liver.
Renal vein thrombosis (obstruction of the renal vein )
A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, causing catastrophic thrombus formation, totally occluding the artery and preventing blood flow downstream.
Drawing of the heart showing anterior left ventricle wall infarction