Coagulation and Dissolution of a Blood Clot

Question 1

Normal hemostasis definition

Answer 1

balance between generation of hemostatic clots and uncontrolled thrombus formation

Question 2

Extrinsic pathway

Answer 2

plasma mediated, initiation of hemostasis

key: tissue factor

Question 3

Intrinsic pathway

Answer 3

amplifies and propagates hemostasis

key: thrombin

Question 4

Common pathway

Answer 4

results in an insoluble fibrin clot

Question 5

Preoperative coagulation testing should be based on

Answer 5

patient’s history and planned surgery

Question 6

Hemostasis is regulated by interactions between

Answer 6

blood vessel walls, circulating platelets, and clotting proteins in the plasma

Question 7

Fibrinolysis definition

Answer 7

orderly breakdown of a stable blood clot

Question 8

Mechanisms of normal hemostasis

Answer 8

vasoconstriction, platelet plug, clot formation, clot dissolution

Question 9

Initiation stage of clot formation

Answer 9

binding of platelets to collagen tissue factor dependent

Question 10

Propagation stage of clot formation

Answer 10

recruitment of platelets to growing thrombus, amplification of clotting cascade

Question 11

Stabilization stage of clot formation

Answer 11

platelet- platelet interaction, fibrin deposition

Question 12

Damage to the endothelium exposes the ECM and causes

Answer 12

vasoconstriction/contraction

Question 13

What can induce prothrombotic endothelial changes?

Answer 13

thrombin, hypoxia, and high fluid sheer stress

Question 14

3 major phases of platelet plug formation

Answer 14

adhesion, activation, and aggregation

Question 15

Normal concentration of platelets

Answer 15

150,000 - 400,000 per microliter

Question 16

Spontaneous bleeding can occur when platelet levels are

Answer 16

< 50,000 u/L, lethal is < 10,000 u/L

Question 17

Life of a platelet

Answer 17

8 - 12 days

Question 18

Where are platelets formed and what is another name for platelets?

Answer 18

In the bone marrow; thrombocytes

Question 19

Inhibitors of platelets

Answer 19

adenosine, insulin, NO, PGE2, PGI2

Question 20

Activators of platelets

Answer 20

adrenaline, cholesterol, GAS6, ICAMs, IGF1, PGE2, sCD40L, thrombopoietin, vWF

Question 21

4 types of platelets

Answer 21

secretory, aggregating, procoagulant, coated

Question 22

Platelet receptors

Answer 22

ADP, TXA2, fibrinogen/vWF, vW factor, collagen

Question 23

Platelet adhesion mechanism

Answer 23

exposure to sub-endothelial matrix proteins allows platelets to undergo conformational change to adhere to the vascular wall

Question 24

Von Willebrand Factor (produced, released, and primary function)

Answer 24

produced in the endothelium and platelets
released by endothelial cells and activated platelets
primary function is to bind to other proteins

Question 25

Glycoprotein IIb/IIIa deals with

Answer 25

platelet to platelet

Question 26

Glycoprotein Ib/factor IX/factor V receptor complex deals with

Answer 26

platelet to vessel wall

Question 27

Glycoprotein Ib-V-IX Complex

Answer 27

binds von Willebrand Factor, allowing platelet adhesion and platelet plug formation at sites of vascular injury

Question 28

Von Willebrand Factor is mainly activated in conditions of

Answer 28

high blood flow and shear stress

Question 29

Which factor goes hand in hand with von willebrand factor?

Answer 29

factor VIII

Question 30

What are 3 "red flags" that could indicate von willebrand disease?

Answer 30

women with heavy menstrual periods, frequent nose bleeds, and gum bleeding with teeth brushing

Question 31

Type 1 vWD

Answer 31

failure to secrete vWF into circulation or vWF clear quickly can be treated with DDAVP

Question 32

Type 2 vWD

Answer 32

decreased ability to bind to GPIb and VIII

Question 33

Type 3 vWD

Answer 33

complete absence of production of VWF

Question 34

Platelet type/pseudo vWD

Answer 34

defect of the platelet's GPIb receptor (vWF is normal)

Question 35

What medications are GPIIb/IIIa inhibitors?

Answer 35

abciximab (ReoPro), eptifibatide (Integrilin), tirofiban (Aggrastat)

Question 36

GPIIb/IIIa inhibitor action

Answer 36

blocks ability of fibrinogen to form around aggregated platelets so no platelet to platelet bridging can occur

Question 37

Which GPIIb/IIIa inhibitor is irreversible?

Answer 37

Abciximab

Question 38

Which medications do we use that are thromboxane A2 inhibitors?

Answer 38

Aspirin | Naproxen

Question 39

Aspirin action

Answer 39

inhibits ability of COX enzyme to synthesize the precursors of thromboxane within platelets

Question 40

What do P2Y12 receptors do?

Answer 40

further amplify the response to ADP and draw forth the completion of aggregation

Question 41

What are ADP receptor antagonists?

Answer 41

ticlopidine (ticlid), clopidogrel (plavix), prasugrel (efient), ticagrelor (brilinta), cangrelor (kengrexal)

Question 42

What completes the formation of a platelet plug?

Answer 42

platelet aggregation

Question 43

blood clot formation

Answer 43

fibrinogen breaks down to produce fibrin that becomes cross linked into a stable mesh activating coagulation factors initiating the coagulation cascade

Question 44

the key step in blood clotting is the conversion of ___ to ___ by ____

Answer 44

fibrinogen; fibrin; thrombin

Question 45

alpha angle on ROTEM

Answer 45

tells how strong the clot will get

Question 46

Intrinsic pathway is triggered when

Answer 46

blood contacts a negatively charged surface

Question 47

Extrinsic pathway is activated when

Answer 47

blood contacts cells outside the vascular endothelium

Question 48

activation of which factor converges the extrinsic and intrinsic pathways?

Answer 48

factor X

Question 49

Which two factors are glycoproteins and not enzymes?

Answer 49

vWF and tissue factor III

Question 50

Which two factors are NOT synthesized in the liver?

Answer 50

Calcium (IV) - diet | Von willebrand - endothelial and platelets

Question 51

Which factors are vitamin K dependent for utilization?

Answer 51

factors II, VII, IX, and X

Question 52

prothrombin gets activated to

Answer 52

thrombin

Question 53

thrombin activates fibrinogen to form

Answer 53

fibrin

Question 54

clot lysis occurs when plasminogen is activated to

Answer 54

plasmin

Question 55

what activates plasminogen?

Answer 55

t-PA (tissue plasminogen activator)

Question 56

plasmin digests

Answer 56

fibrin fibers, fibrinogen, factor V, factor VIII, prothrombin, factor XII

Question 57

What is increased in DIC?

Answer 57

fibrinogen degradation products

Question 58

thrombolytics action

Answer 58

possess fibrinolytic effects or enhances the body's fibrinolytic system by converting endogenous plasminogen to plasmin dissolves newly formed clots

Question 59

prothrombin time (PT)

Answer 59

evaluates extrinsic pathway | reagents vary so INR is used for standardization

Question 60

partial thromboplastin time (PTT)

Answer 60

indicates performance of the intrinsic pathway

Question 61

ACT

Answer 61

reliable for high heparin concentrations influenced by hypothermia, thrombocytopenia, coagulation deficiencies

Question 62

Viscoelastic testing (TEG and ROTEM)

Answer 62

global assay for whole blood clotting

Question 63

1 mg of protamine will inhibit

Answer 63

1 mg (100 units) of heparin

Question 64

normal value for ACT

Answer 64

80 - 150 seconds