Fiser Chaper 2. HEMATOLOGY Flashcards Preview

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Flashcards in Fiser Chaper 2. HEMATOLOGY Deck (90)
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1

Intrinisic pathway

-Exposed collagen, prekallikrein, HMW kininogen, factor 7

--> activate 11

--> activate 9, then add 8

-> activate X, then add V

--> contvert prohrombin (2) to thrombin

-> thrombin converts fibrinogen to fibrin

2

Extrinisic pathway

Injured cells: tissue factor + 7

-> convert prothrombin to thrombin

-> thrombin converts fibrinogen to fibrin

3

Prothrombin complex

10, 5, calcium, platelet facotr 3, prothrombin

Forms on platelets

Catalyzes the formation of thrombin

4

What is the convergent point for intrinsic and extrinsic pathways

X

5

Tissue factor pathway inhibitor does what?

Inhibits factor 10

6

Factor13 does what?

Helps crosslink fibrin

7

Fibrin dose what?

Binds GpIIb/IIIa molecule to link platelets together and form platelet plug

8

Thrombin does what?

Key to coagulation

COnverts fibrinogen to fibrin and fibrin split products

Activates 5 and 13, and platelets

9

Key to normal AC?

Antithrombin III

10

What does AT-III do?

Key to anticoagulation

Binds and inhibits Thrombin

Also inhibits 9, 10, 11

11

How does heparin work?

Activates AT-III (up to 1000x normal activity)

12

Protein C and S

Both vitamin K dependent

C: decreades 5and 8 and fibrinogen

S: protein Ccofactor

13

Fibrinolysis needs what?

Tissue plasminogen activator: released from endothelium and converts plasminogen to plasmin

--> Plasmin degrades factors 5, 8, fibrinogen, fibron

--> lose platelet plug

14

Alpha-2 antiplasmin

Natural inhibitor of plasmin, released from endothelium

15

Shortest half life factor?

7

16

Only factor not synthesized in liver?

8 (endothelium)

17

Vit K dependent factors

2, 7, 9, 10, C and S

18

How long does vit k take?

6 hours to have effect

19

How long does FFP take?

Immediate, lasts 6 hours

20

Half life of RBCs, platelets, PMNs

RBCs: 120 days

Platelets: 7 days

PMNs: 1-2 days

21

PGI2

prostacyclin

from endothelium

decreases platelet aggregation and promotes vasodilation

antagonist to TXA2

22

TXA2

Thromboxane

From platelets

Increases platelets aggregation and vasoconstriction

Triggers release of calciumin platelets --> exposes GpIIb/IIIa receptor and causes platelet-to0platelet binding; platelet-to-collagen binding also occurs (Gp1b receptor)

23

Cryoprecipitate

highest conc of vWF-8; also has fibrinogen

used in vWF disease and hemophilia A

24

FFP

all coag factors, C, S, AT-III

25

DDAVP and conjugated estrogens

Cause release of 8 and vWF from endothelium

26

PT

measures 2, 5, 7, 10, fibrinogen; best for liver synthetic function

27

PTT

measures most factors except 7 and 13 (so does NOT pick up factor 7 def)

28

ACT goals

Activated clotting time

150-200 sec for AC

>460 for cardioplum bypass

29

MCC surgical bleeding

Incomplete hemostasis

30

MCC congenital bleeding disorder

vWF disease

Types 1 (MCC) and 2 are AD, 3 (severe) is autosomal recessive