Fiser Hematology

Question 1

Three initial responses to vascular injury

Answer 1

1. Vasoconstriction.
2. Platelet adhesion.
3. Thrombin generation.

Question 2

Intrinsic Path Start

Answer 2

Exposed collagen + prekallikrein + HMW kininogen + factor XII

Question 3

Extrinsic Path Start

Answer 3

Tissue factor (injured cells) + Factor VII

Question 4

Prothrombin complex components

Answer 4

X, V, Ca, platelet factor 3, prothrombin
Forms on platelets
Catalyzes formation of thrombin

Question 5

Common convergence point for intrinsic/extrinsic paths

Answer 5

Factor X

Question 6

Fibrin - function, binding point

Answer 6

forms platelet plug, binds GpIIb/IIIa molecules

Question 7

Factor XIII function

Answer 7

crosslink fibrin

Question 8

Thrombin function

Answer 8

Convert fibrinogen to fibrin
Activates factors V & VIII
Activates platelets

Question 9

Antithrombin III function

Answer 9

binds & inhibits thrombin
Inhibits F IX, X, XI
Activated by heparin

Question 10

Protein C function

Answer 10

vitamin-K dependent

Degrades V & VIII, fibrinogen

Question 11

Protein S function

Answer 11

vitamin-K dependent, protein C cofactor

Question 12

Tissue plasminogen activator

Answer 12

released from endothelium, converts plasminogen to plasmin

Question 13

Plasmin function

Answer 13

degrades V & VIII, fibrinogen, fibrin –> lose platelet plug

Question 14

Alpha-2 antiplasmin

Answer 14

natural inhibitor of plasmin, released from endothelium

Question 15

Coag factor with shortest half-life

Answer 15

VII

Question 16

Labile factors

Answer 16

V & VIII - activity lost in stored blood, not lost in FFP

Question 17

Only factor not synthesized in liver

Answer 17

VIII - made in endothelium w/ vWF

Question 18

Vitamin K time to effect

Answer 18

12hrs

Question 19

Vit K dependent factors

Answer 19

II, VII, IX, X, proteins C & S

Question 20

Factor II is…?

Answer 20

prothrombin

Question 21

Half-lives of blood components

Answer 21

RBCs = 120d
Platelets = 7d
PMNs = 1-2d

Question 22

Prostacyclin (PGI2)

Answer 22

From endothelium
↓platelet aggregation, ↑vasodilation (antagonist to TXA2)
↑cAMP in platelets

Question 23

Thromboxane (TXA2)

Answer 23

from platelets

↑Platelet aggregation & vasoconstriction

Question 24

TXA2 effect on platelets

Answer 24

Triggers Ca release, exposes GpIIb/IIIa receptor, leads to platelet-to-platelet binding and platelet-collagen binding (GpIb receptor)

Question 25

Cryoprecipitate

Answer 25

Contains highest concentration of vWF-VIII, fibrinogen

Used in vWF disease and Hemophilia A.

Question 26

FFP

Answer 26

highest levels of all coag factors, protein C, protein S, AT-III

Question 27

DDAVP & conjugaed estrogens effect on endothelium?

Answer 27

Can cause release of VIII & vWF from endothelium.