Hemostasis II

Question 1

What are 2 important intrinsic pathway proteins?

Answer 1

Factor XII and Factor XI

Question 2

Activated on contact with negatively charged surface

Answer 2

Factor XII

Question 3

Required for Factor XI to bind to negatively charged surface

Answer 3

HMKG

Question 4

Binds and activates Factor IX

Answer 4

Factor XIa

Question 5

Thrombin activation of Factor XI contributes to propagation of the

Answer 5

Clot

Question 6

Functions in the propagation phase of clot-in conjunction with IXa

Answer 6

Factor XI

Question 7

Associated with minor bleeding phenotype but can be clinically silent

Answer 7

Factor XI deficiency

Question 8

Activates Factors V, VIII, IX, X, XI

Answer 8

Thrombin

Question 9

In the intrinsic pathway, IXa forms complex with cofactor

Answer 9

VIIIa

Question 10

This results in accelerated

Answer 10

Factor X to Xa formation

Question 11

Xa forms complex with cofactor

Answer 11

Va

Question 12

Xa forms complex with cofactor Va. This results in accelerated

Answer 12

Prothrombin to thrombin formation

Question 13

The final step in the intrinsic pathway is

Answer 13

Thrombin cleaves fibrinogen

Question 14

Activated by thrombin

Answer 14

Factor XIII

Question 15

FXIIIa cross-links the

Answer 15

Fibrin chains

Question 16

Extensive cross-linking increases fibrin from dimers to trimers

Answer 16

Tetramers

Question 17

Deficiency is RARE but can cause significant bleeding

Answer 17

Factor XIII deficiency

Question 18

An anticoagulant that regulates coagulation

Answer 18

Thrombomodulin

Question 19

High affinity receptor for thrombin (II)

Answer 19

Thrombomodulin (TM)

Question 20

Neutralizes thrombin’s pro-coagulantactivity

Answer 20

TM

Question 21

Co-factor for thrombin-dependent activation of Protein C

Answer 21

TM

Question 22

Vitamin dependent inhibitors of pro-coagulant systems

-Anticoagulants

Answer 22

Proteins C and S

Question 23

Activated by thrombin-thrombomodulin

Answer 23

Proteins C and S

Question 24

Factor V Activity is regulated by activated

Answer 24

Protein C (aPC)

Question 25

Cleaves factor Va

Answer 25

aPC

Question 26

G-to-A substitution causes Arg to Gln substitution

Answer 26

Factor V Leiden mutation

Question 27

Factor V Leiden Mutation results in increased resistance to

Answer 27

Activated Protein C

Question 28

Inhibits thrombin as well as factor X

Answer 28

Antithrombin

Question 29

Short-acting drug that can only be administered parenterally

Answer 29

Heparin