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47 Cards in this Set
- Front
- Back
Heparin-like molecules. Function?
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Enhance antithrombin III (ATIII) activity.
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Antithrombin III. Function?
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Neutralizes activated serine protease coagulation factors.
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PGI2 (prostacyclin). Function (2)?
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1) Vasodilator
2) Inhibits platelet aggregation |
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Proteins C and S. Function (2)?
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1) Inactivate factors V and VIII
2) Enhance fibrinolysis |
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tPA. Function?
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Activates plasminogen to release plasmin
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Thromboxane A2 (TXA2). Function (2)?
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1) Vasoconstrictor
2) Enhances platelet aggregation |
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vWF. Two functions? Synthesized where?
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a) platelet adhesion, b) prevents degradation of VIII:c in plasma
Synthesized in Weibel-Palade bodies in endothelial cells |
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Factor VIII:c. Synthesized where (2)?
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1) Liver
2) Reticuloendothelial cells |
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In the extrinsic coagulation pathway, what activates factor VII?
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Tissue factor (aka tissue thromboplastin)
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List the important platelet receptors and their cognate ligands (2).
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1) GpIb, vWF
2) GpIIb-IIIa, fibrinogen |
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What is the function of clopidogrel?
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Inhibits expression of GpIIb-IIIa, decreasing platelet aggregation.
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What are three important compounds are stored in platelets?
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1) ADP
2) vWF 3) fibrinogen |
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What molecule is involved in the first step of the extrinsic pathway?
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Factor VII
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What factor is involved in the first step of the intrinsic pathway?
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Factor XII (Hageman factor)
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Which factors are vitamin K dependent (4)?
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1972
factors 10, 9, 7, and 2 |
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What three compounds can activate plasminogen?
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1) tPA
2) streptokinase (from streptococci) 3) urokinase (from human urine) |
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What are D-dimers?
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Cross-linked fibrin monomers
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What is the sequence of events that a platelet goes through in hemostasis of small vessel injury (4)?
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1) adhesion
2) granule release 3) synthesis of TXA2 4) temporary plug formation |
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What holds the temporary platelet plug together (1)?
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fibrinogen
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A temporary plug is converted to a stable plug by the action of ______, which converts _______ to ______.
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a) thrombin
b) fibrinogen c) fibrin |
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What does PTT test?
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The intrinsic system.
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What does PT test?
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The extrinsic system.
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What does D-dimer assay test?
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Fibrin split products. High sensitivity, low specificity.
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What two findings do TTP and HUS have in common?
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1) platelet consumption
2) hemolytic anemia with schistocytes |
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What are some common causes of thrombocytosis (3)?
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1) chronic iron deficiency
2) malignancy 3) splenectomy |
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What is the most common cause of a qualitative (functional) platelet defect?
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Aspirin
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What physical exam sign is only seen with thrombocytopenia?
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Petechiae
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Clinical findings in coagulation disorders (2).
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1) late rebleeding (no stable platelet plug formation)
2) hemarthroses (severe deficiency) |
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What is the mode of inheritance of hemophilia A?
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X-linked recessive
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What is the defect in hemophilia A?
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Factor VIII (intrinsic pathway)
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What is the mode of inheritance of hemophilia B?
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X-linked recessive
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What is the defect in hemophilia B?
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Factor IX deficiency (intrinsic pathway)
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What are laboratory findings for hemophilia A (2)?
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1) decreased VIII:c
2) increased PTT |
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What is the most common hereditary coagulation disorder?
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von Willebrand disease
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What is the mode of transmission of von Willebrand disease?
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Autosomal dominant
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What are the functional abnormalities in vWD (2)?
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1) platelet aggregation disorder (↓ vWF antigen)
2) coagulation factor disorder (↓ VIII:c activity) |
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What laboratory tests will be abnormal in vWD (2)?
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1) ↑ PTT
2) ↑ bleeding time |
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What two important circumstances may lead to vitamin K deficiency?
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1) Newborns with no bacteria
2) Hospitalized patients treated with antibiotics |
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What does warfarin inhibit?
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epoxide reductase
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Liver cirrhosis leads to _____ synthesis of vitamin K-dependent factors and _____ activation of vitamin K.
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a) decreased
b) decreased |
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(True/False) Liver cirrhosis leads to many hemostasis abnormalities leading to increased PT, PTT, bleeding time, and D-dimers.
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True
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What is the most common cause of DIC?
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Sepsis
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What type of coagulopathy is DIC?
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Consumptive
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Why does DIC cause thrombosis and hemorrhage?
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Because it activates the coagulation cascade (thrombosis), but due to consumption of platelets, leads to hemorrhage.
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What are two common anti-phospholipid antibodies?
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1) anticardiolipin antibody
2) lupus anticoagulant |
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What antibody gives a false positive syphilis test?
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anticardiolipin antibody
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What is the most common hereditary thrombosis syndrome?
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Factor V leiden
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