HEMA 2 COAGULATION REGULATORY MECHANISMS

Principal regulators of coagulation regulatory mechanisms.

• TFPI

• APC

• Antithrombin

• ZPI

• Protein S

Kunitz-type serine protease inhibitor

• TFPI

• APC

• AT

• ZPI

Kunitz 2 domain binds to and inhibits ________

• factor Xa

• VIIa:TF complex

• thrombin-thrombomodulin complex

• factor XIa

• factor IXa

Kunitz 1 binds to and inhibits ________

• factor Xa

• VIIa:TF complex

• thrombin-thrombomodulin complex

• factor XIa

• factor IXa

TFPI inhibits coagulation in two-step process by first binding and inactivating TF:VIIa, then binds to Xa forming a quaternary complex and preventing further activation of X and IX.

• TRUE

• FALSE

Answer explanation

TFPI inhibits coagulation in two-step process by first binding and inactivating Xa, then TFPI-Xa complex will bind to TF-VIIa forming a quaternary complex and preventing further activation of X and IX.

Protein S is a cofactor of

• APC

• TFPI

• Antithrombin

• ZPI

Protein S enhances ______ inhibition by TFPI ______

• Xa; tenfold

• Xa; 2000-fold

• TF:VIIa complex; fivefold

• TF:VIIa complex; tenfold

Which of the following triggers the Protein C system?

• thrombin-thrombomodulin complex

• TF:VIIa complex

• TF:VIIa:TFPI:Xa complex

• ECPR:PC complex

Thrombin can be a procoagulant and anticoagulant.

• TRUE

• FALSE

This augments the action of thrombin-thrombomodulin at least fivefold in activating protein C to the serine protease APC.

• ECPR

• Protein S

• Protein Z

• Heparin