Thrombosis Flashcards
What is thrombosis?
Formation of a solid mass in the blood, either in the lumen of vessels or coronary cavities.
Physiological importance of thrombosis?
Normal physiological process in case of vascular injury. Injury lead to blood coagulation and formation of a clot/thrombus.
When is thrombosis a pathological process?
When the blood coagulates without vascular injury.
How can blood flow affect formation of thrombosis?
If blood flow slows down (e.g. due to vasodilatation), the cells in the blood will relocate from the middle of the lumen closer to the wall where they can form clots.
Phases of coagulation process:
- Injured endothelium releases thrombokinase
- Prothrombin in blood changes to thrombin
- Thrombin makes fibrinogen turn into fibrin
Steps in thrombus formation:
- Thrombocyte agglutination
- Fibrinogen coagulation
- Erythrocyte agglutionation
- Plasma protein precipitation
Four types of thrombi
White thrombus
Red thrombus
Mixed thrombus
Hyaline thrombus
What is a white thrombus?
Infectious origin. Consists of thrombocytes, fibrin and leukocytes. Is formed slowly in fast blood flow.
What is a red thrombus?
Dark red. Consists of fibrin and blood components. Formed in slow blood circulation (e.g. venous congestion).
What is a mixed thrombus?
Combination of red and white. Develops when blood flow constantly changes.
What is a hyaline thrombus?
Consists of agglutinated blood components and hyaline. Caused by some infectious diseases and intoxications.
Division of thrombi according to lumen obstruction:
Mural thrombus: attached to a small part of vessel wall (usually bigger vessels)
Occluding thrombus: Completely obstructs the lumen (usually smaller vessels)
What can happen to the thrombus (fate of thrombus)?
May dissolve, become organised or calcify
Potential serious consequences of thrombosis:
May result in severe consequences due to insufficient blood supply, venous congestion, or necrosis
