general homeostasis

Question 1

What are the three natural clotting cascade inhibitors we have talked about?

Answer 1

1) TFPI
2) AT III
3) Proteins S and C

Question 2

How does blood vessel constriction aid clotting?

Answer 2

1) decrease blood loss

2) bring platelets and clotting factors into contact

Question 3

What are the two natural clot lysis agents we have talked about?

Answer 3

1) tPA

2) plasmin

Question 4

What are the two types of granules in platelets and what do they contain?

Answer 4

alpha- fibrinogen and vWf

beta- serotonin, ADP, Ca 2+

Question 5

What factors are involved in the (S)intrinsic pathway?

Answer 5

12, 11, 9, 8, 5

Question 6

What factors are involved in the (S)extrinsic pathway?

Answer 6

TF, 7

Question 7

What factors are involved in the common clotting pathway?

Answer 7

10, thrombin, fibrin

Question 8

What steps of the (S)intrinsic pathway does protein C inhibit?

Answer 8

factors 5 and 8

Question 9

TFPI inhibits tissue factor in which clotting pathway?

Answer 9

the (S)extrinsic pathway

Question 10

What clotting inhibitor inhibits factors 11, 9, TF/ 7 complex, 10, and thrombin?

Answer 10

AT III

Question 11

What is the only example of negative feedback in the clotting cascade?

Answer 11

activated factor 10 inhibits formation of the TF/ 7 complex

Question 12

tPA promotes what?

Answer 12

conversion of plasminogen to plasmin

Question 13

The agent which breaks up clots into Fibrin Degradation Products (FDPs) is what?

Answer 13

plasmin

Question 14

Tissue factor (TF) is released from/present in what locations?

Answer 14

1) “hidden cells” of the sub-endothelium when they are revealed by damage
2) microparticles are always present in the blood
3) endothelial cells and monocytes during inflammation

Question 15

What role do phospholipids in platelet membranes play in clotting?

Answer 15

activate coagulation factors

Question 16

What does glycoprotein (GP) Ia do?

Answer 16

Ia binds collagen

Question 17

Which glycoprotein (GP) binds vWf?

Answer 17

GP Ib

Question 18

What does glycoprotein (GP) IIb/IIIa do?

Answer 18

binds fibrinogen

Question 19

steps for platelet aggregation:

Answer 19

1) proteins exposed
2) platelets adhere
3) granules release
4) platelets aggregate
5) phospholipids exposed

Question 20

steps for fibrin clot formation:

Answer 20

1) TF exposed
2) cascade begins
3) cascade makes fibrin
4) fibrin solidifies plug

Question 21

What does a template bleeding time measure and what would an abnormal result indicate?

Answer 21

evaluates platelet response to injury;

a long bleeding time after incision would indicate a platelet disorder

Question 22

Which platelet test would you use to calculate an “in vitro bleeding time?”

Answer 22

closure time with a platelet function analyzer

Question 23

You would use a platelet function analyzer that measures how fast platelets occlude holes in a membrane to look for what types of platelet disorders?

Answer 23

aspirin related or von Willebrand factor deficiency platelet disorders

Question 24

In a platelet aggregation test where aggregating agents are added singly to the patient sample what are you measuring?

Answer 24

a decrease in sample turbidity would indicate aggregation and thus a deficiency of that added factor in the patient sample

Question 25

Of the two fibrin tests available, which is the more sensitive: FDP assay or fibrinogen assay?

Answer 25

FDP assay, used to rule OUT a minor clot or thrombi

Question 26

What would a decreased fibrinogen assay result indicate?

Answer 26

DIC or a massive bleed

Question 27

Of the two fibrin tests available, which is the more sensitive: FDP assay or fibrinogen assay?

Answer 27

FDP assay, used to rule OUT a minor clot or thrombi

Question 28

What would a decreased fibrinogen assay result indicate?

Answer 28

DIC or a massive bleed

Question 29

What are the steps for completing a coagulation test?

Answer 29

1) draw blood into citrate tube
2) spin tube and decant plasma,
3) add reagents to plasma
4) watch for fibrin formation

Question 30

What factor is added to the patient plasma in a prothrombin time test?

Answer 30

thromboplasin: TF and phospholipids and

Ca +2

Question 31

Where is factor 7 made and what cofactor does it need?

Answer 31

liver, potassium (inhibited by coumadin)

Question 32

What pathway and conditions do we use INR, a corrected PT, to asses?

Answer 32

(S)extrinsic pathway

1) liver function
2) monitor coumadin levels
3) diagnose DIC
4) pre-op status

Question 33

What would the addition of coumadin or heparin or a DIC sample do to prothrombin time (PT)?

Answer 33

an increased prothrombin time

Question 34

What do we use INR, a corrected PT, to asses?

Answer 34

1) liver function
2) monitor coumadin levels
3) diagnose DIC
4) pre-op status

Question 35

What factors are added to a patient plasma sample to calculate partial thromboplastin time?

Answer 35

phospholipid

Question 36

What pathway and conditions do we use PTT to asses?

Answer 36

(S)intrinsic

1) abnormal bleeding
2) monitor heparin levels
3) diagnose DIC
4) diagnose anti-phospholipid antibody production
5) pre-op status

Question 37

What are some conditions that increase PTT?

Answer 37

hemophilia A and B
DIC
presence of Heparin or coagulation pathway inhibitors

Question 38

In which coag test is thrombin added to the patient plasma sample to measure the conversion of fibrinogen to fibrin and why would you run it?

Answer 38

Thrombin time;

if your PTT is prolonged to rule out fibrinogen problems

Question 39

What would an increased Thrombin time indicate?

Answer 39

decreased fibrinogen or increased FDP

Question 40

If your PTT is prolonged but your thrombin time is normal, what test should you order next?

Answer 40

a partial thrombloplastin time (PTT) mixing study

Question 41

When you add pooled plasma and patient plasma to phospholipids for a PTT mixing study, what does it mean if it corrects? If it does not correct?

Answer 41

corrects: the patient is missing a coagulation factor

does not correct: there is an inhibitor in the patient’s plasma