What is Plasminogen?
A precursor to plasmin found in blood and tissue fluid.
What is Plasmin?
An enzyme that breaks down fibrin in blood clots.
What is Fibrin?
A protein that forms the meshwork of a blood clot.
What are Plasminogen activators?
Substances that convert plasminogen to plasmin.
Name two types of Plasminogen activators.
- t-PA
- u-PA
What are anti-activators?
Substances that inhibit the activity of plasminogen activators.
What are PAI-1 & PAI-2?
Plasminogen Activator Inhibitors that regulate fibrinolysis.
What is D-Dimer?
A fibrin degradation product used as a marker for clot formation and breakdown.
What does FDP stand for?
Fibrin Degradation Products.
What is the Coagulation Cascade?
A sequence of events leading to blood clot formation.
What is the initiation phase of coagulation?
The phase where tissue factor binds and activates factor VII.
What is the Extrinsic factor tenase?
The complex of VIIa, TF, phospholipid, and calcium that cleaves factor X.
What role does Xa play in thrombin generation?
Generates a small amount of thrombin by cleaving prothrombin.
What occurs during the amplification phase?
Small amounts of thrombin activate factors V, VIII, and XI.
What is the Prothrombinase complex?
A complex that generates large amounts of thrombin by cleaving prothrombin.
What does thrombin do?
Cleaves fibrinogen to fibrin and activates factor XIII.
What are coagulation factors?
Glycoproteins produced by the liver that participate in coagulation.
List the names of coagulation factors I through XIII.
- I: Fibrinogen
- II: Prothrombin
- III: Thromboplastin
- IV: Calcium ion
- V: Labile factor
- VII: Proconvertin/Stable factor
- VIII: Anti-Haemophilic factor
- IX: Christmas factor
- X: Stuart-Prower factor
- XI: Plasma thromboplastin antecedent (PTA)
- XII: Hageman (contact) factor
- XIII: Fibrin stabilizing factor
What is the role of platelets?
Primary defense against bleeding and formation of a hemostatic plug.
What initiates platelet aggregation?
ADP released from platelets upon adherence.
What is the difference between primary and secondary aggregation?
Primary aggregation is reversible; secondary aggregation is irreversible.
What are natural anticoagulants?
Proteins that inhibit coagulation, including antithrombin III and proteins C and S.
What is the action of antithrombin III?
Inactivates thrombin and enhances its action with heparin.
What is the function of activated protein C (APC)?
Destroys factors VIIIa and Va, preventing further thrombin generation.
