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25 Cards in this Set
- Front
- Back
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What does heparan sulfate do?
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Catalyzes activation of ATIII by heparin
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What does vWF do?
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Tethers platelets to site of vessel wall inury
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What happens to thrombomodulin, heparan, PGI2, and tPA after injury?
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They get stripped away or are no longer produced
This removes anti-coagulants Allows coagulation to proceed towards healing |
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On what cells is tissue factor found (2)?
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Cells of sub-endothelial layer
Monocytes migrating to injury |
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What does "flipase" do?
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Flips PS (phosphotidyl serine) to outside of membranes
Makes PS available to help catalyze reactions |
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What is calcium's role in coag?
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Catalyzes rxns. by promoting attachment of enzymes/zymogens to surface
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PT monitors which pathway?
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Extrinsic pathway
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aPTT monitors which pathway?
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Intrinsic pathway
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In a LAB aPTT, what factors activate the intrinsic coag pathway?
How is this different from in the body? |
Factor XII, prekallikrein, and HMWK
In the body, Factor XI initiates the intrinsic pathway NOTE: deficiencies of FXII and its activators will prolong the aPTT (BUT, they will NOT cause bleeding) |
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What does factor XIII do?
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Transglutaminates fibrin, stabilzing clots
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What is prolonged first in Vitamin K deficiency?
PT or aPTT |
PT
Factor VII falls first, so PT is prolonged |
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What is included in an aPTT assay in a lab (3)?
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"Activator" -- pre-kallikrein, HMWK
Phoshpolipid Calcium |
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What is included in a PT assay in a lab (3)?
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Tissue factor
Phospholipid Calcium NOTE: thromboplastin = tissue factor + phospholipids |
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Where does the Vitamin K dependent carboxylation occur?
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In the liver
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What factors does thrombin feedback affect to accelerate coag?
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Factors V, VIII, XI, XIII
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What is EDTA?
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Calcium chelator
Can be used as an anti-coagulant |
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What is Factor I
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Fibrinogen
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What is Factor II
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Pro-thrombin
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What is Factor III
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Tissue factor
Primary cell initiator of coagulation |
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What is Factor IV
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Calcium
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What is Factor XIII?
What does it do? |
Pro-glutaminase
Cross-links fibrin, stabilizing clots |
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How do oral contraceptives affect coagulation?
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Decrease the effectiveness of anti-thrombin III
May lead to increased venous thromboembolism |
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How do different levels of thrombin affect Factors V and VIII?
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Low levels - accelerate Factors V and VIII
High levels - breakdown Factors V and VIII (via Protein C pathway) |
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What synthesizes Vitamin K-2?
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Bacteria in the gut
NOTE: SO, treatment that kills gut bacteria can cause Vit K def |
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How does bile duct obstruction play into coagulation?
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Vit K is fat-soluble
If bile duct is obstructed, Vit K absorption is compromised |
