| Question |
Answer |
| What is found in the alpha granules of platelets? |
Fibrinogen Fibrinectin VWF Thrombospondin Vitronectin |
| What is found in the dense bodies? |
ADP ATP 5HT Ca |
| Steps of primary hemostasis |
Injured BV has exposed collagen VWF binds collagen GPIb of platelet binds to VWF, causing conformational change in IIb/IIIA IIb/IIIA is now able to bind fibrinogen Platelets express receptors for factors V and VIII; extend pseudopods |
| What role does TXA2 play in coagulation and how does it work? |
TXA2 causes platelet aggregation and vasocontriction. It decreases the level of cAMP, which causes an increase in Ca, which promotes platelet aggregation. |
| How does PGI2 work in coagulation? Where does it come from? |
Opposes the action of TXA2 by increasing the levels of cAMP, which decreases the levels of Ca. This inhibits platelet aggregation. It is released by vascular endothelial cells. |
| What role does ADP play in coagulation? |
Causes platelets to swell and adhere to each other. It then caauses them to release TXA2 and more ADP in a positive feedback mechanism. The clot formed is large enough to fill the injured area. |
| What is the tenase reaction? |
The reaction that causes the formation of Xa (IXa + VIIIa + X) -> Xa |
| What does factor XIII do? |
Provides clot strength and normal wound healing. Without it, clots dissolve more quickly |
| What does ATIII bind to? |
Heparan sulfate |
| What does AT III inactivate? |
IX, X, XI, II |
| What do proteins C and S inactivate? |
Va, VIIIa |
| What does TFPI do? |
Inactivates VIIa-TF complexes |
| What does heparin do? |
Enhances the activity of ATIII (inactivates Ix, X, XI, II) |
| What does warfarin do? |
Binds vitamin K, so II, VII, X, XI, protein C and S are all inhibited |
| What does thrombomodulin do? |
Causes the activation of protein C Also inactivates all the other serine proteases in coagulation |
| What does tPA do? |
Converts plasmingen to plasmin, which then breaks up the clot and releases FSP (D-dimer) |
| What does urokinase do? |
converts plasminogen -> plasmin, forms FSP (d-dimer) |
| What releases tPA and urokinase? |
Endothelium Fibrin |
| What does PAI-I do? |
down-regulates plasmin |
| What is alpha-2-anti-plasmin? |
Inhibits fibrinolysis, by collecting free plasmin |
| IL-11 |
Allows for increasing the number of circulating platelets |
| C-MPL |
TPO receptor on platelets |
| Treatments for VWD |
DDAVP Intermediate Purity Factor |
| What is Intermediate Purity Factor |
Combination of VWF and factor VIII; used to treat VWD |
HHS Shrek
