Hemostasis

Question 1

Number of platelets an average megakaryocyte generates is approximately:

Answer 1

2000-4000

Question 2

Normal platelets have a circulating lifespan of approximately:

Answer 2

10 days

Question 3

Platelets interacting with and binding to other platelets is referred to as:

Answer 3

Aggregation

Question 4

Alpha granules are found on the platelet in the:

Answer 4

Organelle zone

Question 5

Anticoagulant required for routine coagulation

Answer 5

Sodium citrate

Question 6

Dilution of anticoagulant for coagulation studies

Answer 6

1:10

Question 7

Anticoagulant in a blood specimen collected from a polycythemic patient should be:

Answer 7

Reduced in volume

Question 8

If a physician suspects a qualitative platelet defect, the most useful test to order is:

Answer 8

Bleeding time

Question 9

Platelet aggreg studies: Normal response to ADP, collagen, epinephrine; no response with ristocetin

Answer 9

von Willebrand disease

Question 10

Which of the coagulation factors is considered labile?

Answer 10

V

Question 11

APTT test reagent is composed of:

Answer 11

Calcium ions & Phospholipids

Question 12

APTT monitors ____ therapy.

Answer 12

Heparin

Question 13

PT test reagent is composed of:

Answer 13

Calcium & thromboplastin

Question 14

A prolonged thrombin time and a normal reptilase time is characteristic of:

Answer 14

Therapeutic heparinization

Question 15

Hemophilia B is a disorder that presents with a decrease in Factor ___.

Answer 15

IX

Question 16

Fibrin strands are cross-linked and the fibrin clot is stabilized by the activity of :

Answer 16

Factor XIIIa

Question 17

A deficiency of protein C is associated with increased risk of ____.

Answer 17

Thrombosis

Question 18

A patient on warfarin therapy will be deficient in a functional amount of:

Answer 18

Protein C & S

Question 19

Patient on therapeutic warfarin: ____ PT, ____ APTT, ____ BT, ____ platelet count

Answer 19

Increased; increased; normal; normal

Question 20

Reversal of heparin overdose can be achieved by administration of:

Answer 20

Protamine sulfate

Question 21

If a patient presents with a prolonged APTT that does not correct upon mixing, the next to be performed should be:

Answer 21

DRVVT

Question 22

The activity of the lupus anticoagulant and anticardiolipin antibodies appears to be directed against:

Answer 22

Phospholipid

Question 23

Megakaryocyte progenitors arise from the CMP under the influence of the transcription gene product, ____, regulated by cofactor ____.

Answer 23

GATA-1; FOG1

Question 24

Nuclear lobularity first becomes apparent as an indentation at the ___ stage, rendering the cell identifiable as an MK-II stage.

Answer 24

4N

Question 25

The platelet membrane surface called the ____, absorbs albumin, fibrinogen, and other plasma proteins.

Answer 25

Glycocalyx

Question 26

On further activation, in conjunction with aggregation, platelets change in shape from discoid to ____ and extend ____.

Answer 26

Round; pseudopods

Question 27

Phosphatidylserine is the polar phospholipid on which the factor ____ and factor ___ complexes assemble.

Answer 27

IX/VIII (tenase); X/V (prothrombinase)

Question 28

____ control cellular activation for all cells at the inner membrane surface; abY heterotrimers that bind GDP when inactive.

Answer 28

G-proteins

Question 29

Preferred & other names: Factor V

Answer 29

Proaccelerin | Labile factor, accelerator globulin (aCg)

Question 30

Preferred & other names: Factor VII

Answer 30

Proconvertin | Stable factor, serum prothrombin conversion accelerator (SPCA), autoprothrombin I

Question 31

Preferred & other names: Factor VIII

Answer 31

``` Antihemophilic factor Antihemophilic globulin (AHG), antihemophilic A, platelet cofactor 1 ```

Question 32

Preferred & other names: Factor IX

Answer 32

Plasma thromboplastin | Christmas factor, antihemophilic factor B, platelet cofactor 2

Question 33

Preferred & other names: Factor X

Answer 33

Stuart-Power factor | Stuart factor, Power factor, autoprothrombin III

Question 34

Preferred & other names: Factor XI

Answer 34

Plasma thromboplastin antecedent (PTA) | Antihemophilic factor C

Question 35

Preferred & other names: Factor XII

Answer 35

Hageman factor | Glass factor, contact factor

Question 36

Preferred & other names: Factor XIII

Answer 36

Fibrin-stabilizing factor | Laki-Lorand factor, fibrinase, fibrinoligase, serum transglutaminase

Question 37

Other names: HMWK

Answer 37

Fitzgerald factor, Flaujeac factor, Williams factor, contact activation factor

Question 38

Other name: Prekallikrein

Answer 38

Fletcher factor

Question 39

What is the largest fragment of the FDPs?

Answer 39

Fragment X

Question 40

Which fragments are the most important in exerting anticoagulant effects?

Answer 40

X & Y

Question 41

Which fragments inhibit fibrin polymerization?

Answer 41

Y & D

Question 42

Which fragment is a powerful inhibitor of thrombin?

Answer 42

E

Question 43

What is the principle inhibitor of coagulation?

Answer 43

Antithrombin III

Question 44

This test which uses coagulant properties of Russel's viper venom was used to help distinguish between FX & FVII deficiencies

Answer 44

Stypven time

Question 45

What are the factors present in adsorbed plasma?

Answer 45

I, V, VIII, XI, XII

Question 46

What are the factor present in aged serum?

Answer 46

VII, IX, X, XI, XII

Question 47

Platelet estimation on PBS: How many platelets should be normally seen/OIF?

Answer 47

8-20

Question 48

There are approximately ____ red cells per platelet in normal peripheral blood.

Answer 48

10-40

Question 49

In Pseudoxanthoma Elasticum, ____ are the most common causes of death.

Answer 49

Subarachnoid & GI bleeding

Question 50

Purpura associated with abdominal pain, secondary to GIT bleeding

Answer 50

Henoch's purpura

Question 51

Purpura associated with join pain esp the knees and ankles

Answer 51

Schonlein's purpura

Question 52

Triad of Wiskott-Aldrich syndrome

Answer 52

Thrombocytopenia, recurrent infections, eczema

Question 53

Triad of Hermansky-Pudlak syndrome

Answer 53

Tyrosinase-(+) oculocutaneous albinism, accumulation of ceroid-like pigment in macrophages, bleeding tendency

Question 54

Triad of Chediak-Higashi syndrome

Answer 54

Albinism, recurrent infections, giant lysosomes

Question 55

These are proteins that precipitate when plasma is diluted with water and acidified

Answer 55

Euglobulins

Question 56

This is a test for secondary FDPs, resulting to a fel formation

Answer 56

Protamine sulfate gelation test

Question 57

What is the reason behind a biphasic curve in aggregation studies?

Answer 57

Initial phase: interaction of the agent with the platelet | Second phase: release of nonmetabolic ADP from platelet granules

Question 58

vWF molecules are stored in ____ in platelets and in ____ in ECs.

Answer 58

a-granules; Weibel-Palade