Exam

Clotting Pathway

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Clotting Pathway, Clotting Cascade, Coagulation Pathway, Clotting Factor, Coagulation Factor

  • Images
  1. Overview
    1. pathClottingCascade.png
  • Physiology
  • Pathways
  1. Initiators of the Clotting Cascade
    1. Intrinsic Clotting Pathway
      1. Initiated by Negatively charged surface
    2. Extrinsic Clotting Pathway
      1. Initiated by disrupted cell membranes
  2. Common Clotting Pathway follows above initiators
    1. Antagonized by Clotting Pathway Inhibition
  3. Factors
    1. Activation
      1. All of these Clotting Factors (both pro-coagulant and Anticoagulant) are Vitamin K Dependent
      2. Vitamin K is required for carboxylation of terminal ends of coagulation proteins
      3. Without carboxylation, Clotting Factors/proteins are not activated and Clotting Cascade does not occur
      4. Warfarin inhibits the cyclic interconversion of Vitamin K to a reduced form
        1. Keeps Vitamin K and dependent factors inactive
    2. Procoagulant Factors (Mnemonic: 1972)
      1. Factor 10 (half life 36 hours)
      2. Factor 9 (half life 24 hours)
      3. Factor 7 (half life 7 hours)
      4. Factor 2 (half life 50 hours)
    3. Anticoagulant Factors
      1. Protein C (half life 8 hours)
      2. Protein S (half life 30 hours)
  • Labs
  1. Partial Thromboplastin Time (PTT)
    1. Measures intrinsic pathway
    2. Prolonged by
      1. Factor VIII Deficiency (Hemophilia A)
      2. Factor IX Deficiency (Hemophilia B)
  2. Prothrombin Time (PT)
    1. Measures extrinsic pathway
  3. Affecting both ProTime and Partial Thromboplastin Time
    1. Factor X
    2. Factor V
    3. Prothrombin
    4. Fibrinogen
  4. Thrombin Time
    1. Measures only common pathway