Hemostasis

Question 1

normal hemostasis sequence

Answer 1

1. endothelial injury/dysfunction with reflex vasoconstriction
2. clot initiation/formation (primary hemostasis)
3. clot propagation/stabilization (secondary hemostasis)
4. clot inhibition/cessation (antithrombotic activity)
5. clot dissolution (fibrinolysis)

Question 2

Virchow’s triad

Answer 2

1. endothelial injury
2. abnormal blood flow
3. hypercoagulability

Question 3

gray platelet syndrome

Answer 3

alpha-granule deficiency, mild bleeding

Question 4

ADP

Answer 4

strong signal for platelet aggregation

Question 5

Glanzmann thrombasthenia

Answer 5

GPIIb-IIIa deficiency (aggregation problem)

Question 6

Bernard-Soulier syndrome

Answer 6

GPIb deficiency (adhesion problem)

Question 7

von Willebrand disease

Answer 7

vWF deficiency (adhesion problem)

Question 8

intrinsic pathway initiation

Answer 8

negatively charged suface (glass beads)

Question 9

extrinsic pathway initiation

Answer 9

tissue factor (in vivo)

Question 10

intrinsic pathway

Answer 10

XII > XI > IX > X > prothrombin > fibrinogen

Question 11

extrinsic pathway

Answer 11

TF > VII > IX > X > prothrombin > fibrinogen

Question 12

Vit K and Ca2+ dependent factors

Answer 12

VII, IX, X, and II

Question 13

XIII deficiency

Answer 13

scabs fall off easily > scar

Question 14

intrinsic tenase complex

Answer 14

VIIIa-IXa

Question 15

extrinsic tenase complex

Answer 15

TF-VII-Ca2+

Question 16

Prothrombin time (PT)

Answer 16

time to clot (evaluates extrinsic and common pathways)

Question 17

activated partial thromboplastin time/activated clotting time (aPTT/ACT)

Answer 17

used to detect abnormalities in blood clotting and evaluate heparin treatment (evaluates intrinsic and common pathways)

Question 18

warfarin (coumadin)

Answer 18

anti-vit K drug, targets extrinsic pathway (VII, IX, X, II)

Question 19

heparin

Answer 19

activates antithrombin III, targets intrinsic pathway

Question 20

low molecular weight heparin

Answer 20

only targets Xa, less risk of bleeding

Question 21

PrC and PrS

Answer 21

inhibit the accelerators of coagulation (VIIIa and Va)

Question 22

PrC and PrS deficiencies

Answer 22

hypercoagulable state

Question 23

antithrombin (III)

Answer 23

inhibits coagulation, targets IIa, IXa, Xa, XIa, and XIIa

Question 24

XIIa pathway (fibrinolysis)

Answer 24

XIIa converts plasminogen to plasmin, breaks down fibrin

Question 25

XIIa deficiency

Answer 25

hypercoagulable state

Question 26

tissue plasminogen activator (fibrinolysis)

Answer 26

t-PA converts plasminogen to plasmin, breaks down fibrin

Question 27

urokinase (fibrinolysis)

Answer 27

urokinase converts plasminogen to plasmin, breaks down fibrin

Question 28

factor V Leiden mutation (hypercoagulable)

Answer 28

resistance to activated Pr C

Question 29

prothrombin mutation (hypercoagulable)

Answer 29

too much prothrombin

Question 30

heparin-induced thrombocytopenia (HIT) (hypercoagulable)

Answer 30

formation of auto-Abs to heparin + platelet factor 4 > clotting

Question 31

antiphospholipid autoantibodies

Answer 31

common with lupus, syphilis, multiple miscarriages > clotting

Question 32

vWD Types 1 and 3

Answer 32

reduced quantity of circulating vWF. | Type 3 also has low circulating vWF.

Question 33

hemophelia A

Answer 33

factor VIII deficiency, X-linked recessive

Question 34

hemophelia B

Answer 34

factor IX deficiency, X-linked recessive, "Christmas disease"

Question 35

hemophelia C

Answer 35

factor XI deficiency, autosomal recessive, less severe, ne joint bleeding, prolonged bleeding from trauma and nosebleeds (Ashkenazi Jews and Basque)

Question 36

Vit K deficiency

Answer 36

defective II, VII, IX, X, Pr S, C, and Z. Increased PT.

Question 37

Platelet adhesion test

Answer 37

ristocetin-induced vWF: GpIb. Defect: Bernard-Soulier syndrome.

Question 38

Platelet aggregation tests

Answer 38

ADP/collagen/epinephrine/arachidonic acid/ thrombin agonist-induced aggregation: GpIIb. Defect: Glanzmann thrombasthenia.

Question 39

acute immune (idiopathic) thrombocytopenic purpura (ITP)

Answer 39

auto-Abs against GpIIbIIIa, childhood disease, self-limited, resolves in months

Question 40

chronic ITP

Answer 40

20% of acute childhood ITP becomes chronic (>6 months)

Question 41

chronic immune (refractory) thrombocytopenic purpura (ITP) of adults

Answer 41

auto-Abs against GpIIbIIIa, 3F:1M | Rx: splenectomy, immune modulators

Question 42

thrombotic microangiopathies (TMAs)

Answer 42

hemolytic anemia with anisocytosis, reticulocytosis, elevated LDH, and thrombocytopenia.

Question 43

Thrombotic thrombocytopenia purpura (TTP) (TMA)

Answer 43

ADAMTS13 deficiency

Question 44

Shiga toxin-producing E coli hemolytic uremic syndrome (STEC-HUS) (TMA)

Answer 44

E. coli strain 0157, bloody diarrhea

Question 45

hemolysis, elevated liver enzymes, low platelet count (HELLP) (TMA)

Answer 45

pregnant women with HTN, +/- proteinuria

Question 46

Waterhouse-Friderichsen syndrome

Answer 46

massive adrenal hemorrhages

Question 47

plasma

Answer 47

includes coagulation factors

Question 48

serum

Answer 48

coagulation factors removed