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30 Cards in this Set
- Front
- Back
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What are the events in primary, secondary, and tertiary hemostasis?
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Primary Hemostasis:
- Platelet adhesion - Platelet aggregation - Platelet plug formation Secondary Hemostasis: - Coagulation pathway Tertiary Hemostasis: - Crosslinking of fibrin and factor 13 - Fibrinolysis |
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In Primary hemostasis, vWF binds to exposed collagen, what platelet protein binds to vWF?
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GP1B/V/IX binds vWF
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What are in alpha granules of platelets? (7)
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P-selectin
PDGF PF4 Platelet fibrinogen Thromboglobulin Thrombospondin vWF |
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What are in delta (dense) granules of platelets? (4)
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ADP
ATP Serotonin Ca2+ |
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After the platelet plug is formed, what platelet protein is involved in platelet aggregation? What binds to the protein?
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In platelet aggregation, GPIIb/IIIa binds fibrinogen.
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In addition to converting fibrinogen to fibrin, what else does factor IIa (thrombin) do?
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Thrombin activates F5, 8, 11, 13.
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What is the formula for calculating INR?
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INR = [(Patient PT)/(Normal mean PT)]^ISI
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What does ISI stand for?
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ISI = International Sensitivity Index (related to amount of tissue factor in reagent)
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What factor deficiency presents with normal PT and PTT?
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Factor 13 deficiency
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What is the purpose of reptilase time?
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Reptilase time:
1. A way of getting around heparin contamination. RT is not increased even if there is heparin. 2. An increased RT indicates dysfibrinogenemia. |
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These classes of disorders do not have secondary phase with epinephrine and ADP in platelet aggregation studies.
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Storage pool defects, aspirin
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What is defect in Bernard-Soulier syndrome? What is the function of the defective protein?
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Defect in GP1B/5/9. GP1B/5/9 binds to vWF during platelet adhesion in primary hemostasis.
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What is the typical finding in Bernard-Soulier?
PT PTT BT Platelet aggregation study Plt count Blood smear Clot retraction test |
What is the typical finding in Bernard-Soulier?
PT: normal PTT: normal BT: increased Platelet aggregation study: Everything (ADP, Epi, Collagen) is normal except ristocetin aggregation Plt count: decreased Blood smear: large platelets Clot retraction test: normal |
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What is the defect in Glanzmann thrombasthenia? What is the function of the defective protein?
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Defect in GP2b/3a. GP2b/3a binds to fibrinogen in platelet aggregation during primary hemostasis.
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What is the typical finding in Glanzmann thrombasthenia?
PT PTT BT Platelet aggregation study Plt count Blood smear Clot retraction test |
What is the typical finding in Glanzmann thrombasthenia?
PT: normal PTT: normal BT: increased Platelet aggregation study: the only normal thing is ristocetin Plt count: normal Blood smear: normal Clot retraction test: no retraction |
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This autosomal dominant disease due to mutated myosin heavy chain 9, is characterized by giant platelets and Dohle bodies in granulocytes on blood smear.
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May-Hegglin anomaly
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What is the defect in gray platelet syndrome?
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No alpha granules
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What syndrome lacks delta granules and has Swiss cheese platelets?
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Hermansky-Pudlak syndrome
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What is the only type of vWD treated by DDAVP?
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Type 1
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What is the defect in type 2b and pseudo-vWD?
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2B: vWF with increased affinity for GP1b/5/9 (platelet receptor in adhesion of primary hemostasis) resulting in consumption of large vWF multimers without injury.
Pseudo-vWD: Defective GP1b/5/9 with increased affinity for vWF. |
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What is 2M vWD?
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Defective vWF which can't bind GP1b/5/9 well.
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What is 1 Bethesda unit?
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1 BU = 50% activity of the factor
NOTE: 2 BU = 25%; 3 BU = 12.5%, etc... |
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What is the function of vitamin K and which are the vitamin K dependent factors?
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Function: carboxylation of gluatmate residues to form gamma-carboxyglutamate residues.
K-dependent: 2, 7, 9, 10, C, S |
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What additive causes pseudothrombocytopenia? What does the smear look like?
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EDTA, platelet satellitism
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What is the typical triad of HUS?
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Microangiopathic hemolytic anemia, thrombocytopenia, acute renal failure
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What is the typical pentad of TTP?
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Microangiopathic hemolytic anemia, thrombocytopenia, neurological symptoms, acute renal failure, fever
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What is the defect in factor 5 Leiden?
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Factor 5a is immune to inactivation by protein C.
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What are the 2 most common mutations causing factor 5a to be immune to inactivation by protein C?
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1. Factor V Leiden: glycine to arginine at 506 (G506R).
2. Factor V Cambridge: threonine to arginine at 306 (T306R). |
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What is the mechanism of heparin induced thrombocytopenia? What is the timeframe in which it develops?
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Mechanism: IgG Ab to heparin PF4 complex in alpha granules
Timeframe: 5-8 days after starting unfractionated heparin |
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What makes vWF?
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Megas and endothelial cells
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