Hemostasis and Coagulation

Question 1

Mediators responsible for inhibition of platelet aggregation?

Answer 1

PGI2
NO
ADPase

Question 2

Molecules that bind and inhibit thrombin

Answer 2

Heparin-like molecules (which accelerate anti-thrombin III inactivating thrombin)

Question 3

Activity of thrombomodulin?

Answer 3

Activated Protein C, which leads to lysis of Factors 5 and 8

Question 4

What does alpha 2 macroglobulin do?

Answer 4

Binds thrombin for removal from the circulation

Question 5

Antithrombotic properties of resting endothelial cells (6)

Answer 5

1. Inhib. platelet aggregation
2. Binds+Inhibits thrombin
3. Thrombomodulin
4. Synth. protein S: cofactor for protein C
5. alpha2 macroglobulin
6. Fibrinolysis

Question 6

Three prothrombotic properties of activated endothelium

Answer 6

1. Endothelial cell injury leads to platelet aggregation/adhesion
2. Activation of coagulation cascade
3. Inhibition of fibrinolysis

Question 7

How do activated ECs activate the coagulation cascade?

Answer 7

Tissue factor synthesis induced by cytokines or bacteria, which activates Factor 7

Question 8

Three important actions of platelets upon activation

Answer 8

1. Adhesion/Shape Change
2. Secretion
3. Aggregation

Question 9

Platelet adhesion to the subendothelium requires _____ and _____ receptor

Answer 9

von Willebrand’s factor

GpIb receptors

Question 10

What do platelets secrete?

Answer 10

Alpha Granules and Dense Bodies

Question 11

What binding is important for platelets’ role in primary plug formation

Answer 11

GpIIb-IIIa and fibrinogen

Question 12

Contents of Platelet alpha granules

Answer 12

fibrinogen, fibronectin, V, VIII, PF-4, PDGF, TGF-b

Question 13

Contents of electron dense bodies

Answer 13

ADP, ATP, Ca, histamine, serotonin, epinephrine

Question 14

Most important mediators of platelet aggregation

Answer 14

ADP

TxA2, thrombin

Question 15

Intrinsic pathway is activated by ______ in vitro

Answer 15

Hageman Factor

Question 16

Antithrombins inhibit…

Answer 16

Thrombin
AND
9a, 10a, 11a, 12a

Question 17

Protein C and S inactivate…

Answer 17

5 and 8

Question 18

Two types of plasminogen activators

Answer 18

Urokinase-like plasminogen activators

tissue-type plasminogen activators

Question 19

When are urokinase-like plasminogen activators used

Answer 19

In fluid phase (serum/tissue)

Question 20

When are tissue type plasminogen activators used?

Answer 20

Made by endothelium, activated when bound to fibrin

Question 21

Decreased vW factor will also cause a lower level of….

Answer 21

8