Thrombosis in the Wrong Place Flashcards
What does coagulation prevent?
→Blood loss
What is coagulation?
→An immunological response
What are the steps for the contact activation pathway?
Factor 12 → activated factor 12 activated factor 12 → Activated factor 11 Activated factor 11 → Activated factor 9 Activated factor 9 → Activated factor 10 Pro thrombin → Thrombin
What is the intrinsic pathway activated by?
→ Damaged surfaces
Activated when blood is exposed to collagen (or other damaged surfaces or like charged platelets)
What are the steps for the extrinsic pathway?
Factor 7 → activated factor 7
Tissue factor → activated factor 10
Prothrombin → Thrombin
What is the extrinsic pathway activated by?
→ trauma
Begins in the vessel wall.
Damaged endothelial cells release factor III (tissue factor)
What is reverse thrombosis?
→ Fibrinolysis
What happens when tissue is damaged/inflammation?
→ Platelets become activated
→ Fibrinogen turns into fibrin by thrombin
What does arterial thrombosis result from?
→ Atheroma rupture or damage to the endothelium
What is arterial thrombosis described as?
→ Platelet rich ‘white’ thrombosis
What can arterial thrombosis do to arteries downstream?
→ May block arteries downstream
What does venous thrombosis result from?
→ From stasis or a hypercoagulant state DVT
What is venous thrombosis described as?
→ Platelet poor ‘red’ thrombosis
What can venous thrombosis do?
→ move to the lungs
What do endothelial cells express?
→ Factors inhibiting coagulation
What does tissue plasminogen activator do?
→ Activates Plasminogen to Plasmin
→ Plasmin carries out lysis of the clot to D Dimers.
What do subendothelial cells release if they are disturbed?
→ Tissue factor
→ Von Willebrand Factor
What is Virchow’s triad?
STASIS
→ Static blood lacks kinetic energy and tends to clot. Stasis also slows the washout of activated clotting factors and impedes the inflow of clotting factor inhibitor
HYPER-COAGULANT STATE
→ Infection, hereditary or drugs (HRT)
ENDOTHELIAL DAMAGE
→when endothelium gets ripped up is that tissue factor is exposed (which initiates the coagulation cascade).Surgery or cannula
How is blood returned to the heart in veins?
→ Contraction of nearby muscles squash veins
What does blood do around valves?
→ Tends to eddy around valves which increases the risk of stasis