Pathology of Thrombosis and Embolism Flashcards
Vichrow’s triad
changes in intimal surface vessel
changes in the pattern of blood flow
changes in the blood constituents
Ischaemia
poor blood flow
Hypoxia
severe ischaemia leads to decreased oxygenation of tissue
Anoxia
an absence or deficiency of oxygen reaching the tissues; severe hypoxia
necrosis
process of a tissue dying in any manner
Infarction
necrosis as a result of ischaemia
can occur in other tissue:
coronary heart thrombosis = infarct in heart
cerebral artery thrombosis = infarct in brain
mesenteric artery thrombosis = infarct in gut
Why does ischaemia often lead to hypoxia
in severe or total blockage of blood flow this leads to lack of oxygen
embolism
mass of material moving in the vascular system and able to become lodged in a vessel and block its lumen
most emboli are derived from thrombi or clots
they break off and go elsewhere in the circulation
when thrombi/clots embolise its called
pulmonary embolism process
sluggish flow in leg veins leads to thrombosis and clot formation
part of thrombus breaks off and travels up vein
embolus passes into inferior vena cava, then right heart, then pulmonary trunk, and lodges in pulmonary artery branch
embolus blocks pulmonary artery and get pulmonary infarct
Marrow embolism process
fracture leg
marrow enters ruptured vein
marrow embolism to lung vessels
air embolism process
knife wound to neck
air enters vein
air embolises to heart
example of Virchow’s triad
Atheroma - disease of coronary artery
results in a build up of lipid can result in abnormal blood flow
lipid (and collagen) can also rupture through intimal surfaces
platelets and fibrin are now exposed to an abnormal substance and turbulent flow and deposited as thrombus
clot forms behind thrombus in coronary artery at stagnant blood
