Steps of clotting
1. Hemostasis/Temporary clot formation – It is formed by the aggregation of platelet at the site of injury.
2. Formation of permanent clot – Most accepted theory of blood clotting is Cascade Theory by Macfarlane and his co-workers. It requires the 13 clotting factors
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Fibrinogen
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Prothrombin
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Thromboplastin (Tissue factor)
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Ca++ ion
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Labile factor / Proaccelerin
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Hypothetical factor / Accelerin
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Proconvertin factor / Stable factor
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Anti Haemophilic factor – AHF
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Christmas factor / Plasma thromboplastin component (PTC)
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Stuart factor / Prower factor
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Plasma thromboplastin antecedent(PTA)
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Hagman factor / Surface factor / Contact factor / Glass factor
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Fibrin stabilizing factor (FSF) / Laki Lorand factor (LLF)
When blood clotting is triggered by VII factor it is called as Extrinsic mechanism.
When blood clotting is triggered by XII factor it is called as Intrinsic mechanism.
