Coagulation Cascade

Question 1

What causes the primary hemostasis

Answer 1

The injury to the blood vessel

Question 2

When platelets are activated, what do the expose in their conformational change

Answer 2

A phospholipid platform which allows for adhesion of other platelets

Question 3

Define tissue factor

Answer 3

Produced by injured endothelial cells

Converts FVII to FVIIa in the extrinsic pathway

Question 4

Other name for:

FI
FII 
FIII 
FIX
FX
FXII 
FXIII

Answer 4

Fibrinogen 
Prothrombin 
TF
Christmas Factor 
Stuart-Power Factor 
Hageman  Factor 
FSF

Question 5

What are the Vit-K dependent factors

Answer 5

II, VII, IX, X

Question 6

What does Vit. - K do

Answer 6

Introduces Ca binding sites via y-carboxylation of glutamic acid which allows these factors to use Ca and fully function

Question 7

What does PTT test for

Answer 7

Intrinsic pathway

XII, HMWK, XI, IX, and VIII

Question 8

What does PT test for

Answer 8

Extrinsic pathway

VII

Question 9

What can an abnormal PTT test indicate clinically

Answer 9

Heparin therapy

Hemophilia A or B

Question 10

Define Hemophilia A factor issue

Answer 10

FVIII

Question 11

Define Hemophilia B issue

Answer 11

FIX

Question 12

What does PTT ACTUALLY LOOK AT

Answer 12

The clotting time from FXII to fibrin clot in the intrinsic pathway

Question 13

What can PT indicate clinically

Answer 13

Coumadin therapy

Vit. K deficiency

Question 14

What does PT actually look at

Answer 14

Clotting time from FVII to fibrin clot in the extrinsic pathway

Question 15

What is the extrinsic pathway activated by

Answer 15

External trauma

Question 16

What is the intrinsic pathway activated by

Answer 16

Trauma inside the vascular system, and activated by platelets, exposed endothelium, or collagen

Question 17

Vit. K is not active till when

Answer 17

Converted from its quinone form to its quinol form in the liver

Question 18

What converts Vit. K from Vit K 2,3-epoxide to quinone form

Answer 18

Vit. K 2,3 - epoxide reductase

Question 19

What converts quinone Vit. K to active quinol Vit. K

Answer 19

Quinone reductase

Question 20

What does wardarin act on

Answer 20

Decreases the activity of Vit. K - epoxide reductase, which increases the time it takes for clot to form

Question 21

What is the more active form of warfarin and what is it metabolized by

Answer 21

S-warfarin which is metabolized by CYP2C9

Question 22

Which factors have the longest half-life

What about the shortest

Answer 22

FII and FX

FVII

Question 23

What does an increased PT and a decreased PTT mean

Answer 23

Liver disease and decreased Vit. K and VII

Question 24

What does a normal PT and prolonged PTT mean

Answer 24

Defective intrinsic pathways, vWD, lupus

Question 25

What does it mean if both PT and PT are prolonged

Answer 25

Defective FI, II, V, or X, severe liver disease, or warfarin OD

Question 26

What is the purpose of HMWK

Answer 26

Acts as a cofactor with XII to attract it to the charged surface of the platelet

Question 27

What is the purpose of Kallikrein

Answer 27

Accelerates conversion of XII to XIIa through positive feedback