Thrombosis, embolism, ischaemia and infarction Flashcards
What are the steps of thrombus formation in an arterial vessel?
- RBC and platelets flow through arterial vessels without touching sides
- Collagen exposed underneath when endothelial cells lift up when damaged
- Laminar flow disrupted
- Platelets bind to collagen and release chemicals to attract more platelets
- Platelets bind to other platelets → platelet aggregation
- Fibrinogen → fibrin
- Thrombosis that blocks vessel can form with RBC and platelets stuck
What is a thrombosis?
Solid mass of blood constituents formed within intact vascular system during life
What can a thrombus be produced by?
-Change in vessel wall
-Change in blood flow
-Change in blood constituents
What is a thrombus in an arterial vessel caused by?
Change in vessel wall + change in blood flow
What are the steps of thrombus formation in a venular vessel?
- Slow blood flow, will touch sides
- Cells may stick to endothelial cells
What is a thrombus in a venular vessel caused by?
Change in blood flow
How does COVID cause thrombosis?
COVID causes changes in clotting factors,
inflammation boosting cytokines
What is an embolus?
Mass of material in the vascular system able to become lodged within vessel and block it
Where do most emboli occur?
In veins
What can be a result of emboli and thrombosis?
Ischaemia
What is ischaemia?
Reduction in blood flow
What is infarction?
Death of cells due to reduction in blood flow
What organ is supplied by 1 artery?
Kidney
What happens to an organ with 1 blood supply that becomes blocked?
That part of the organ dies
What organs have 2 blood supplies?
Lungs, liver, some parts of brain (circle of Willis)
