Hemostasis and Liver

Question 1

The 2b-3a receptor binds? What does it mediate?

Answer 1

Fibrinogen; mediates aggregation

Question 2

The 1a-5-9 receptor binds? Mediates?

Answer 2

vWF

platelet adhesion

Question 3

Which granules contain clotting factors, and which ones?

Answer 3

Alpha
1 (fibrinogen)
5 and 8

Question 4

Name 3 global assays for platelets

Answer 4

buccal mucosal bleeding time
thromboelastography
aperture closure instruments

Question 5

You don’t need to worry about platelet bleeds until numbers are below?

Answer 5

30,000

Question 6

How can EDTA skew thrombocytopenia?

Answer 6

it chelates Ca and can expose previously hidden spots of the platelet to the immune system

Question 7

What does buccal mucosal bleeding time evaluate for?

Answer 7

Primary hemostasis

Question 8

How will vWD affect clot retraction?

Answer 8

It won’t

Question 9

Extrinsic vs. intrinsic platelet disorders?

Answer 9

Extrinsic–platelets are normal

Intrinsic–platelets are abnormal

Question 10

A disease inherited by CKCS

Answer 10

inherited macrothrombocytopenia

Question 11

Does inherited macrothrombocytopenia cause clinical bleeding?

Answer 11

NO

Question 12

vWD is what type of platelet disorder?

Answer 12

Extrinsic (lacking vWF) but platelets are normal

Question 13

How is vWF activated?

Answer 13

binds to exposed collagen and sheer force of the flowing blood forces the binding site to be exposed

Question 14

What are the 3 types of vWD?

Answer 14

Type 1–vWF low, but present (most common)
Type 2– vWF function is altered
Type 3– vWF is absent

Question 15

What is Glanzmann Thrombasthenia? How is it inherited? Name 2 predisposed breeds

Answer 15

a reduction in the 2b-3a receptor (impaired platelet aggregation)
Autosomal recessive
Otterhouse, great pyrenees

Question 16

How will Glanzmann Thrombasthenia affect clot retraction?

Answer 16

it will be absent

Question 17

What does the CalDAG-GEFI mutation cause?

Answer 17

it alters the ability of the signaling cascade to change the 2b-3a receptor from low to high affinity

Question 18

Two important factors of the EXTRINSIC pathway?

Answer 18

VII and III

Question 19

Order of activation in the INTRINSIC pathway

Answer 19

XII–>XI–>IX (VIII) –> X

Question 20

X, V, & II are considered part of the ______ pathway

Answer 20

common

Question 21

After the extrinsic pathway is shut down by ______; thrombin activates which factors to sustain coagulation?

Answer 21

TFPI

V, VIII, IX, XIII
also protein C

Question 22

Why is factor XIII important?

Answer 22

clot stability (cross-linking of fibrin)

Question 23

Which factors are vitamin K dependent

Answer 23

II, VII, IX, X

Proteins C and S

Question 24

Which factor has the shortest half-life

Answer 24

VII

Question 25

Which factors are inhibited by Antithrombin

Answer 25

Thrombin (II), X, and the intrinsic pathway factors (XII, XI, IX)

Question 26

Which pathway of plaminogen activation is fibrin specific?

Answer 26

Extrinsic

Question 27

Which coag test uses whole blood? All the rest use?

Answer 27

ACT

citrated plasma

Question 28

Which tests screen the intrinsic and common pathways

Answer 28

ACT, APTT

Question 29

Which test screen the extrinsic and common pathways?

Answer 29

PT

Question 30

Which test directly measures fibrin?

Answer 30

TT

Question 31

With vWD, APTT will be ____

Answer 31

normal

Question 32

What does an increase (>20) of FDP indicate?

Answer 32

uncompensated DIC

Question 33

D dimers are the products of

Answer 33

fibrin that’s been cross-linked by XIII

Question 34

Hemophilia diseases are associated with with factors?

Answer 34

VIII (A)

IX (B)

Question 35

3 differentials for acquired hemostatic disorders

Answer 35

1) vitamin K deficiency/antagonism
2) Liver disease
3) DIC

Question 36

Which test will prolong first with Vit K deficiency and why

Answer 36

Extrinsic

Factor VII has shortest half life