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Flashcards in Defects of Coagulation mechanism Deck (55)
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1

What are the 3 main types of bleeding disorders?

acquired platelet defects
inherited bleeding disorders
acquired coagulopathy

2

What is hemostasis?

process that prevents blood loss form damaged blood vessels

3

What is thrombosis?

pathological formation of a 'hemostatic' plug within the vascularture in the absence of bleeding
(excesive hemostasis)

4

What important factor is needed for platelet adhesion? Receptor?

vWF
GPIbalpha

5

What important factor is needed for platelet aggregation? Receptor?

Fibrinogen
GPIIb/IIIa

6

What is contained in dense granules in the platelet?

ADP, ATP
seratonin
calcium

7

What does calcium release lead to?

integrin activation
granule secretion

8

What are the 2 binding domains on vWF?

Gp1b
GPIIb/IIIa

9

What does binding of vWF with GP1b cause?

braking/activation of the platelet

10

What does binding of vWF ith GPIIb/IIIa cause?

arrest of the platelet

11

What does platelet granule release lead to?

signals other platelets

12

What does platelet membrane coagulant expression lead do?

thrombin and clot

13

Initiation phase of cell based coagulation

activaion of IXa & Xa
Xa converts II to IIa (thrombin)

14

Amplification phase of cell based coagulation

thrombin activated Va, VIIIa, XIa and platelets

15

Propagation of cell based coagulation

IXa catalyzing further thrombin formation
XIa augments by driving further IXa formation

16

Thrombin driven pahse of cell based coagulation

transformation of fibrinogen to fibrin and cross linking

17

What are the vitamin K dependent pro coagulant factors?

II, VII, IX, X

18

What are the vitamin K dependent anti coagulant factors?

Proteins C & S

19

What does thrombin activate?

Fibrinogen to fibrin
Factor XIIIz
TAF1

20

What does an intrinsic pathway deficiency lead to?

increased PTT

21

What does an extrinsic pathway deficiency lead to?

increased PT

22

What enzymes are important for the fibrinolytic system?

t-PA
Plasminogen
alpha-antiplasmin
D-dimer

23

What does active protein C do?

proteolysis of factors Va and VIIa

24

What does mucosal bleeding usually indicate?

platelet defect of vWF

25

What does deep tissue bleeding usually indicate?

factor deficiency

26

Generalized oozing at venipuncture sites is indicative of?

DIC

27

What are screening tests done for platelet phase problems?

platelet count
PFA-100

28

What are screening tests done for coagulation phase problems?

PT
PTT
Fibrinogen
Inhibitor screening (1:1 mix)

29

How do we check for quantitative defects of platelets?

peripheral blood film
Vit B12, PF4 ELISA

30

What causes decreased platelet production?

vit B12 deficiency
marrow failure or disease