The Cascade System (PART 2) Flashcards Preview

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Flashcards in The Cascade System (PART 2) Deck (23):
1

Which pathway is being tested by Prothrombin Time (PT)

Extrinsic Pathway

2

Which pathway is being tested by Activated Partial Thromboplastin Time (APTT)

Intrinsic Pathway

3

List the correct order of activation of factors for in vitro testing by the Prothrombin Time (PT)

- VII
- X
- V
- II
- I

4

List the correct order of activation of factors for in vitro testing by the activated partial thromboplastin time (APTT)

- XII (plus Fletcher and Fitzgerald )
- XI
- IX
- VIII
- X
- V
- II
- I

5

List the correct order of activation factors for the common pathway

X, V, II, I

6

What is the role of prothrombinase complex in the common pathway?

Macromolecular complex which forms on the surface of the platelets; great amplifier of thrombin activation
- (made up of Xa, Va, PL, and calcium)

7

How is the unstable, soluble fibrin monomer formed in the common pathway?

- Fibrinogen is composed of three pairs of polypeptide chains (alpha, beta, and gamma)
- Thrombin cleaves a portion of the alpha and beta to form fibrinopeptides A and B
- After the cleavage, the fibrinogen molecule is called a fibrin monomer
- fibrin monomer quickly polymerizes (line up side by side) to form fibrin (unstable w/ loose hydrogen bonds)

8

What factor is responsible for forming the stable, insoluble fibrin clot

Factor XIII and calcium convert loose hydrogen bonds to stronger covalent (cross-linked) bonds

9

List four hemostatic actions of thrombin

1. converts fibrinogen to fibrin
2. activates factors XI, V, VIII, and XIII
3. Induces platelet aggregation
4. Binds the endothelial cell membrane protein, thrombomodulin, to activate the protein C pathway

10

Nomenclature of the two portions of the Factor VIII complex

von Willebrand Factor and Factor VIII:c

11

Site of synthesis of the two portions of the Factor VIII complex

vWF: endothelial cells and megakaryocytes
VIII: Liver

12

Principle biologic activity of the two portions of the Factor VIII complex

vWF: carrier for factor VIII
VIII: corfactor for X to Xa

13

Clinical disorder due to deficiency of the two portions of the Factor VIII complex

vWF: von Willebrand's Disease
VIII: Hemophilia A

14

Which Factor VIII complex is responsible for normal bleeding time?

* vWF

15

Which Factor VIII complex is responsible for normal platelet adhesion

*vWF

16

Which Factor VIII complex is responsible for ristocetin co-factor activity

*vWF

17

List the coagulation factors present in the fibrinogen group

- I
- V
- VIII
- XIII

18

List the coagulation factors present in the prothrombin group

- II
- VII
- IX
- X

19

List the coagulation factors present in the contact group

- XI
- XII
- PK
- HMWK

20

Which coagulation factors are consumed or destroyed during clotting?

I, V, VIII (VII:C/vWF), XIII, II
(fibrinogen group AND II)

21

Which coagulation factors are dependent upon vitamin K for synthesis

II, VII, IX, X (prothrombin group)

22

Which coagulation factors are destroyed by plasmin

I, V, VIII, XIII (fibrinogen group)

23

Which coagulation factors are heat labile

I, V, VIII, XIII (fibrinogen group)