Hemostasis and Thrombosis Flashcards Preview

MCM Test 1 > Hemostasis and Thrombosis > Flashcards

Flashcards in Hemostasis and Thrombosis Deck (31):
1

What is hemostasis?

process of blood clotting at the site of vascular injury

2

What is a hemorrhagic disorder?

too little clotting

3

What is a thrombotic disorder?

too much clotting

4

What are the main cells involved in hemostasis?

platelets and endothelium

5

What are the humoral factors involved in hemostasis?

plasma proteins and cellular contents

6

What is the difference in function between primary and secondary hemostasis?

primary: makes platelet plug
secondary: platelet plug made stronger with fibrin mesh addition

7

List the main steps in hemostasis.

vasoconstriction > primary hemostasis > secondary hemostasis > thrombus and antithrombotic events

8

What factor binds platelets to the site of injury?

von Willebrand factor

9

What protein allows platelets to interact with vW factor?

glycoprotein 1B (GpIb)

10

What protein facilitates platelet aggregation?

glycoprotein 2b3a complex (GpIIb-IIIa)

11

What are the main steps of primary hemostasis?

1. platelet adhesion (vW factor)
2. shape change
3. granule release (ADP, TxA2)
4. recruitment
5. aggregation (hemostatic plug)

12

What are the two types of laboratory secondary hemostasis?

intrinsic
extrinsic

13

What coagulation factors are associated with the intrinsic secondary pathway?

XII, XI, IX, VIII

14

What coagulation factors are associated with the extrinsic secondary pathway?

VII, tissue factor

15

What coagulation factors are common between the intrinsic and extrinsic pathways?

X, V, II (prothrombin), I (fibrinogen)

16

Which ion immobilizes factors to the surface of the platelet plug?

Calcium

17

What factors does thrombin upregulate?

XI, VIIIa, Va

18

What coagulation factors are used in vivo during secondary hemostasis?

tissue factor, VII, IX, X, VIII, XI, X, V, II (prothrombin), I (fibrinogen)

19

What stops the formation of the fibrin clot?

fibrinolytic system

20

What enzyme cleaves fibrin into fibrin degradation products?

plasmin

21

What circulating protein precipitates plasmin?

plasminogen (inactivated form)

22

What prevents excessive fibrin degradation?

binding of free plasmin to alpha2 antiplasmin

23

Which enzymes positively affect the fibrinolysis system?

tissue plasminogen activator (tPA) and urokinase

24

Which enzymes negatively affect fibrinolysis?

plasminogen activator inhibitors (PAI)

25

Which natural anticoagulant process inactivates thrombin?

antithrombin III + heparin like molecules

26

How are factors Va and VIIIa inactivated?

with a combo of protein C and S

27

What compounds released from endothelial cells inhibit platelet aggregation?

PGI2, NO, and adenosine diphosphatase

28

What tests primary hemostasis?

Bleeding time/PFA-100

29

What tests the intrinsic pathway?

PTT

30

What tests the extrinsic pathway?

PT

31

What tests fibrinolysis?

D-Dimer (show clotting degradation)