Coagulation/Platelets

Question 1

primary hemostasis consists of

Answer 1

platelet adherence, activation, and aggregation

Question 2

what do platelets initially adhere to?

Answer 2

exposed sub endothelium via vWF

Question 3

what does activation of platelets entail

Answer 3

shape change and release of granule contents

Question 4

what is secondary hemostasis

Answer 4

activation of coagulation, generation of thrombin

Question 5

what initiates coagulation

Answer 5

tissue factor

Question 6

IIa function

Answer 6

thrombin (IIa)- removes 4 fibronopeptides, allows conversion of fibrinogen to fibrin

Question 7

thrombomodulin function

Answer 7

enhances activation of PC by IIa

Question 8

release of tPA causes

Answer 8

plasminogen conversion to plasmin

Question 9

what does plasmin do

Answer 9

breaks up fibrin chains

Question 10

what is elevated in DIC

Answer 10

plasma D-dimers

Question 11

2 main deficiencies of hemophilia

Answer 11

factor VIII or IX (VIII is more common)

Question 12

why is hemophilia more common in males?

Answer 12

because it is X-linked

Question 13

treatment of hemophilia

Answer 13

IV injection of factor VIII or IX

Question 14

clinical phenotype of severe hemophilia

Answer 14

spontaneous soft tissue and joint bleeds

Question 15

clinical phenotype of moderate hemophilia

Answer 15

only after minor injury or surgery

1-5% coagulation factor level

Question 16

clinical phenotype of mild hemophilia

Answer 16

post-op and post-trauma bleeding

5-40% coagulation factor level

Question 17

population that is at high risk for factor XI deficiency

Answer 17

Ashkenazi Jews

Question 18

when is prothrombin time prolonged

Answer 18

II, V, VII, X, or fibrinogen are reduced

Question 19

what does NOT affect PT

Answer 19

VIII, IX, XI, XII, PK, or HMWK levels

Question 20

when is PTT prolonged

Answer 20

if any factor (except VII) is low

Question 21

what factor does NOT affect either PT or PTT

Answer 21

XIII

Question 22

sources of acquired bleeding disorders

Answer 22

liver dysfunction
vitamin K deficiency
disseminated intravascular coagulation (DIC)

Question 23

what factors need vitamin K to function

Answer 23

II, VII, IX, X, protein C and protein S

Question 24

function of vitamin K

Answer 24

changes conformation of proteins so that they bind phospholipid membranes

Question 25

what are 3 coagulation inhibitors

Answer 25

protein C protein S antithrombin

Question 26

what is the most common cause of hereditary thrombophilia

Answer 26

Factor V Leiden

Question 27

what does Lupus Anticoagulants do to the PTT

Answer 27

prolongs it

Question 28

in the case of thrombosis and/or recurrent pregnancy loss, check for

Answer 28

lupus anticoagulants, autoimmune disease

Question 29

action of heparin

Answer 29

enhance binding of AT and Thrombin

Question 30

purpose of INR

Answer 30

standardize the reporting of test results for patients taking coumadin

Question 31

dabigatran

Answer 31

direct thrombin inhibitor

Question 32

rivaroxaban, apixaban

Answer 32

direct Xa inhibitor

Question 33

purpura fulmina is associated with

Answer 33

group A beta hemolytic streptococcus

Question 34

clinical conditions associated with DIC

Answer 34

``` bacterial sepsis burns extensive trauma placental abruption hypoxia ```

Question 35

cause of DIC

Answer 35

exposure of patient's blood to tissue factor

Question 36

ASA action

Answer 36

anti platelet drug | inhibits prostaglandin synthesis

Question 37

Dipyridamole action

Answer 37

elevates cAMP by inhibition of phosphodiesterase

Question 38

clopidogrel, prasugrel, ticagrelor action

Answer 38

interferes with ADP binding

Question 39

abciximab action

Answer 39

inhibition of GP IIb/IIIa

Question 40

2 pathways essential for platelet activation

Answer 40

phosphoinositide hydrolysis pathway eicosanoid pathway

Question 41

dense granule contents

Answer 41

ADP, ATP, serotonin- amplify platelet activation

Question 42

lysosomal granule contents

Answer 42

proteases and glycosidases

Question 43

how is platelet bleeding different than coagulation factor abnormality bleeding?

Answer 43

platelet factor: bruises, petechiae, everywhere. coagulation factor- hemorrhage into joints, soft tissues

Question 44

cause of ATP

Answer 44

bound anti-platelet antibodies (IgG)- increased platelet destruction

Question 45

platelet size correlates with

Answer 45

megakaryocyte number

Question 46

platelet diameter correlates inversely with

Answer 46

platelet survival

Question 47

vWF function

Answer 47

carrier for FVIII and adhesive link between platelets and injured blood vessel wall

Question 48

vWD cause

Answer 48

defective binding of platelets to injured vessel walls, then to each other. prolonged bleeding time

Question 49

where is vWF stored

Answer 49

alpha granules of platelets and in the Weibel-Palade body organelle in endothelial cells

Question 50

most common vWD

Answer 50

type 1- scattered mutations, autosomal dominant mutants with inhibition of secretion

Question 51

thrombotic thrombocytopenic purpura

Answer 51

acute onset of platelet consumption

Question 52

risk factors of TTP

Answer 52

HIV, SLE, pregnancy, drugs, e. coli

Question 53

features of TTP

Answer 53

``` thrombocytopenia hemolytic anemia- microangiopathic, reticulocytes increased LDH neurological symptoms renal impairment fever NO DIC ```

Question 54

etiology of TTP

Answer 54

increased vWF multimers- lead to platelet clumping under shearing conditions

Question 55

ADAMTS-13 absence is associated with

Answer 55

Thrombotic thrombocytopenic purpura