Haemostasis, Thrombosis And Embolism Flashcards
What factors does the success of Haemostasis depend on?
The vessel wall, platelets, the coagulation system and the fibrinolytic system.
How do blood vessels assist in Haemostasis?
They constrict to limit blood loss in a process that is not fully understood.
What are the factors involved in the cogulation system?
The cascade amplification, where are series of inactive component are converted to active components, resulting in the transformation of prothrombin to thrombin, which converts fibrinogen to fibrin that can go onto to form a clot.
What is the role of platelets in homeostasis?
Adhere to damage on the vessel wall and adhere to one another to form a platelt plug. There is a platekt release reaction which used ATP-ADP to form ADP trombaxne which causes platelet aggregation, Platelet factor 3 is important in coagulation and platelets coalesce after aggregation.
What are some of the factors involved in the control of cogulation?
Thrombin inhibitors (Porteins C and S, alpha1 antitrypsing, alpha 2 macroglobubn and antithrombin 1)
What is Thrombosis?
The formation of a solid mass of blood in the circulatory system
What are some of the reasons that thrombosis can occur?
Abnormalities of the vessel wall, abnormalities in blood flow and abnormalities of the blood components.
What are some of the features of appearance of arterial thrombi?
Ple, granular, lower cell content and lines of Zahn
What are some of the features of the appearance of venous thrombi?
Soft, geltantinous, deep red with a higher cell content
What are the possible outcomes of a thrombus?
Propagation, Lysis, Organisation, reacnlisation and embolism
How does a thrombus propogate?
This is the spread of a trombus, which happens distally in ateries and proximally in veins, and the thrombus cause turbulent flow when another artery or vein joins upstream causing the formation of more thrombi
How does lysis of a thrombus occur?
Is more likely when the thrombus is small, this is complete dissolution of the thrombus caused by the action of the fibrinolytic system.
What is the proccess of recanalisation of a thrombus?
One or more channels is formed through the thrombus, bloodflow is restored but usually is incomplete.
What is the proccess of organisation of a thrombus?
It is reparative process, the lumen remains obstructed and the ingrowth of fibroblasts and capillaries occurs which is similar to the formation of granulation tissue.
What are the arterial affects of a thrombus?
Ischemia, infarction and depends on the site and the collateral circulation.
