Exam 2 Secondary Hemostasis and Clotting Factors Flashcards
Define secondary hemostasis
The processes involving the reactions of coagulation proteins through a cascade-like process that concludes with the formation of an insoluble fibrin clot.
List the four groups of coagulation proteins/chemicals.
Enzyme precursors (zymogens); non-enzymatic (cofactors); ionized calcium (Ca++); phospholipids
What is a zymogen?
Inactive coagulation factor that is converted to an active form by an enzyme; Cofactors II, VII, IX, X, XI, XII, and prekallikrein
What is a cofactor?
A non-protein chemical compound or metallic ion that is required for an enzyme’s activity as a catalyst
What are proagulant cofactors
Coagulation factors
What are serine proteases?
A group of proteolytic enzymes that digest peptide bonds creating a new active factor
What is thrombin?
Principle serine protease of coagulation; turns fibrinogen into fibrin
What is prothrombin?
Plasma precursor of the coagulation factor thrombin; converted to thrombin by Xa
What are the vitamin K dependent cofactors?
II, V, VII, IX, X
What are the factors in the intrinsic pathway?
I, II, VIII, IX, X, XI, XII, prekallikrein, and kininogen
What factors are in the extrinsic pathway?
I, II, VII, X
What factors are in the common pathway?
I, II, V, VIII, X
What factor can be deficient but rarely causes displays bleeding tendencies?
Factor XII
What is the intrinsic pathway?
Occurs after trauma happens within the vein such as exposed endothelium; it’s slower – takes about ten minutes after platelet plug is started until fibrin is formed but it is more important; subendothelial collagen triggers the activation of a set of coagulation factors called the Intrinsic Pathway
What is the extrinsic pathway?
Occurs when Tissue Factor is released – blood is exposed to extracellular tissue fluid; Tissue Factor (Tissue Thromboplastin)(Factor III) – is secreted by the endothelial cells following injury – triggers a set of coagulation factors
