Intrinsic and Extrinsic Pathways Study Deck Flashcards
What is factor I?
Fibrinogen
What factor number is fibrinogen?
Factor I
What is the first factor to become activated in the intrinsic pathway?
Factor XII (Hageman factor)
What is factor II?
Prothrombin
What factor number is prothrombin?
Factor II
What is factor III?
Tissue factor (TF)
What factor number is tissue factor?
III
What is factor IV?
Calcium ion (Ca2+)
What factor number is calcium?
IV
What is factor V?
proaccelerin
What factor number is proaccelerin?
V
What is factor VII?
proconvertin
What factor number is proconvertin?
VII
What happens after factor 12 (Hageman factor) is activated?
Activated factor 12 activates factor 11 (plasma thromboplastin antecedent).
What happens after factor 11 (plasma thromboplastin antecedent) is activated?
Activated factor 11 activates factor 9 (plasma prothrombin component). It requires Calcium to do this.
What is factor VIII?
Antihemophilic factor
What factor number is antihemophilic factor?
VIII
What is factor IX?
plasma thromboplastin component
What factor number is plasma thromboplastin companent?
IX (nine)
What is factor X?
Stuart factor
What number factor is Stuart factor?
X
What is factor XI?
plasma thromboplastin antecedent
What number factor is plasma thromboplastin antecedent?
XI
What is factor XII?
Hageman factor
What factor number is Hageman factor?
XII
What is factor XIII?
Fibrin stabilizing factor
What factor number is fibrin stabilizing factor?
XIII
What happens when factor 9 is activated?
There is the addition of phospholipid surfaces of aggregated platelets. Along with active factor IX, it activates factor VIII then together it creates an activate factor IX/active factor 8 complex.
What happens after tissue factor is activated?
With the addition of Calcium, it activates factor VII (proconvertin). This creates a tissue factor/active factor 7 complex.
Within both the intrinsic and extrinsic pathways, what leads to active factor 10?
activate factor IX/active factor 8 complex (intrinsic) and tissue factor/active factor 7 complex (extrinsic).
What creates prothrombin activator?
Consists of active factor X, active factor V, calcium and phospholipid surface.
What are crucial components to both pathways?
Negatively charged membranes (glass, metal, collagen)
What are some characteristics of the intrinsic pathway?
Called intrinsic because the factors needed for clotting are present within (intrinsic to) the blood.
Triggered by negatively charged surfaces such as activated platelets, collagen, or glass. (The negative charges on glass explain why this is the pathway that initiates clotting outside the body in test tubes.)
Slower because it has many intermediate steps.
What are some characteristics of the extrinsic pathway?
Called extrinsic because the tissue factor it requires is outside of blood.
Triggered by exposing blood to a factor found on cells in tissues surrounding the blood vessel. This factor is called tissue factor (TF) or factor III.
Faster because it bypasses several steps of the intrinsic pathway. In severe tissue trauma, it can form a clot in 15 seconds.
Describe the common pathway to thrombin.
Prothrombin activator catalyzes the conversion of a plasma protein called prothrombin into the active enzyme thrombin.
Describe the common pathway to the fibrin mesh.
The end point of phase 3 is a fibrin mesh that traps blood cells and effectively seals the hole until the blood vessel can be permanently repaired. Thrombin catalyzes the transformation of the soluble clotting factor fibrinogen into fibrin. The fibrin molecules then polymerize (join together) to form long, hairlike, insoluble fibrin strands. The fibrin strands glue the platelets together and make a web that forms the structural basis of the clot. Fibrin makes the liquid plasma become gel-like and traps formed elements that try to pass through it
What is the pathway and function of fibrinogen?
Common pathway; converted to fibrin (insoluble weblike substance of clot)
What is the pathway and function of prothrombin?
Common pathway; converted to thrombin (converts fibrinogen to fibrin)
What is the pathway and function of tissue factor?
Extrinsic path; activated extrinsic path
Where is the source of fibrinogen?
Liver
Where is the source of prothrombin?
Liver
Where is the source for tissue factor?
Tissue cells
What is the pathway and function of calcium?
Needed for essentially all stages of coagulation; always present
What is the source of calcium?
plasma
What is the pathway and function of proaccelerin (factor V)?
common pathway; part of the prothrombin activator complex
Where is the source for proaccelerin (factor V)?
Liver, platelets
What is the pathway and the function of proconvertin (factor VII)?
external pathway, creates the active factor 7 and tissue factor complex
What is the source of factor VII (proconvertin)?
Liver
What is the pathway and the function for antihemophilic factor?
Intrinsic pathway; makes the active factor 9/active factor 8 complex that activate factor 10
What is the source of antihemophilic factor?
liver and lung capillaries
Where is the source for factor 13 (fibrin stabilizing factor)?
liver and bone marrow
What is the function of factor 13?
cross-links fibrin, forming a strong stable clot
