Coagulation

Question 1

Activated platelets at the site of injury release what vasoconstrictors?

Answer 1

Thromboxane A2 and serotonin

Question 2

What initiates platelet tethering?

Answer 2

Glycoprotein receptor 1ba (GP1ba) binds exposed vWF

Question 3

What occurs immediately after platelet tethering?

Answer 3

GPVI binds collagen in ECM

Question 4

What occurs after GPVI binds collagen in platelet adhesion and activation?

Answer 4

Factors released by platelets bind to G protein coupled receptors on platelets already bound to injury site - positive feedback activation

Question 5

What leads to the ability of platelets to bind fibrinogen?

Answer 5

Conformational change in GPIIa/IIIb following platelet activation

Question 6

What acts as a molecular glue between activated GPIIa/GPIIIb on platelets?

Answer 6

Fibrinogen

Question 7

What facilitates platelet-platelet interactions?

Answer 7

GPIIa/IIIb

Question 8

What is an example of autocrine signaling in platelet activation?

Answer 8

Thromboxane A2 receptor activated by TXA2

Question 9

What activates protease activated receptors (PARs)?

Answer 9

Thrombin

Question 10

What are the ligands for glycoproteins on platelets?

Answer 10

Collagen, vWF, fibrinogen

Question 11

What are the ligands for G protein coupled receptors on platelets?

Answer 11

TXA2, ADP, thrombin

Question 12

What are the roles of NO and PGI2?

Answer 12

1. Vasodilation 2. Anti-platelet adhesion

Question 13

What cleaves fibrinogen to form fibrin monomers?

Answer 13

Thrombin

Question 14

What clotting factor does thrombin activate?

Answer 14

XIII

Question 15

What does factor XIIIa do?

Answer 15

Induces fibrin fibers to cross link to form stable insoluble clot

Question 16

What is the name of clotting factor 1?

Answer 16

Fibrinogen

Question 17

What is the name of clotting factor 2?

Answer 17

Prothrombin

Question 18

What is the name of clotting factor 3?

Answer 18

Tissue factor

Question 19

What is the name of clotting factor 4?

Answer 19

Calcium

Question 20

What is the (start of) the common clotting pathway?

Answer 20

Prothrombin —-> thrombin mediated by factor Xa and Va

Question 21

What is the role of factor Va?

Answer 21

Combines with factor Xa to speed up thrombin production 1000x

Question 22

What does exposure of tissue factor (III) do?

Answer 22

1. Activates factor VII 2. Activates factor X 3. Both of these activate factor X

Question 23

What initiates the intrinsic pathway?

Answer 23

Factor XII is exposed to collagen (activated)

Question 24

What is the activation cascade after factor XII in the intrinsic pathway?

Answer 24

12 –> 11 –> 9 –> 10 –> Prothrombin / thrombin

Question 25

What is the tenase complex?

Answer 25

1. Made up of factor VIIIa + IXa2. Accelerates activation of Xa

Question 26

Hemophilia is a deficiency in which clotting factor?

Answer 26

8

Question 27

What are the vitamin K cofactors in the clotting cascade?

Answer 27

10, 9, 7, 2

Question 28

What does activated partial thromboplastin time monitor?

Answer 28

Speed of intrinsic pathway

Question 29

What does the prothrombin time assay measure?

Answer 29

Extrinsic pathway

Question 30

What are the two anticoagulation mechanisms?

Answer 30

1. Preventing thrombin mediated clot 2. Destroying preformed thrombin

Question 31

Degrading what two clotting factors will significantly reduce thrombin formation?

Answer 31

Va and VIIIa

Question 32

What is the result of a protein c deficiency?

Answer 32

Hypercoagulation

Question 33

What is the result of a thrombomodulin deficiency?

Answer 33

Hypercoagulation

Question 34

How does the tissue factor pathway inhibitor reduce thrombin formation?

Answer 34

Inhibiting factor VIIa / tissue factor complex

Question 35

What must antithrombin do to speed thrombin proteolysis 1000x?

Answer 35

Bind to heparin sulfate

Question 36

What is the main protease that cleaves fibrin?

Answer 36

Plasmin