Cascade Players
At what molecule do the intrinsic and extrinsic pathway merge?
What is Xa
Fibrinolytics cleave fibrin polymers; anticoagulants do this instead.
Prevent the formation of fibrin polymers
This single factor is unique to the extrinsic pathway where it binds to tissue factor of damaged cells
VII
A 2-week old patient with severe umbilical cord stump bleeding, prolonged bleeding with circumcision, and petechiae was diagnosed with a rare factor X mutation. What were the results of his PT and PTT?
PT and PTT will both be prolonged.
The active form of this zymogen activates another zymogen to form clots.
What is prothrombin
(active to thrombin which converts fibrinogen to fibrin)
Classify Warfarin and tPA
warfarin is an anticoagulant and tPA is a fibrinolytic
These four factors are unique to the intrinsic pathway
XII-->XI-->IX-->VIII
These two players activate the extrinsic pathway.
What is VIIa and Tissue Factor (TF)
This anticoagulant activates antithrombin III which then inhibits thrombin and Xa.
What is Heparin
These players belong in the common pathway, which follows both the intrinsic and extrinsic pathways.
What is X-->V-->II (prothrombin)-->I (fibrinogen)
DAILY DOUBLE!!!
WAGER!
In order to form a stable mesh, fibrin forms polymers to be crosslinked by this player.
What is Factor XIII
This molecule is added to the plasma in PT but not in PTT
What is Tissue Factor
A deficit in factor XI will cause a change in this test.
What is PTT (contact activation, -TF)
What is Factor XII
Clinical testing measures levels of this product of the breakdown of fibrin.
D-dimer
These two factors are actually considered cofactors as they interact with factor IXa and Xa. respectively.
VIIIa interacts with IXa to activate, and Va interacts with Xa.