Module 3: Mechanisms of Normal Hemostasis (from review sheet) Flashcards Preview

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Flashcards in Module 3: Mechanisms of Normal Hemostasis (from review sheet) Deck (61):
1

Hemostasis

prevention and arrest of bleeding by rapid repair of nay ruptures in blood vessels

2

5 components of hemostasis

vascular
platelet
coagulation system
fibrinolytic system
natural anticoagulants and inhibitors

3

3 things secreted by endothelial cells that make them thromboresistant

heparin sulfate
Prostacyclin
nitrous oxide

4

2 types of vasoconstriction after injury

muscular
humoral (delayed due to release of endothelin)

5

endothelin

secreted by endothelial cells
induces smooth muscle contraction for vasoconstriction

6

2 things released by injured tissue

Tissue thromboplastin (III)
Tissue Plasminogen Activator (TPA)

7

Tests for vascular response (3)

bleeding time
closure test
capillary fragility test

8

why is Thrombopoiesis different from other cells (2)

megakaryocytic get bigger as they mature
no cellular division

9

platelet lifespan in blood

8-10 days

10

3 zones of platelet

peripheral
sol gel
organelle

11

peripheral zone

plasma membrane
outer coating
glycocalyx
Important for adhesion and aggregation

12

Sol gel zone

cytoskeleton with contractile proteins thrombosthenin and actomyosin
importnat in plt retraction, shape changes, viscous metamophosis in secondary aggregation

13

Organelle zone

canicular system, dense bodies, alpha granules (PF3, fibrinogen, thrombospondin, PF4), dense tubular system (stores Ca2+)
Important in plt retraction and prostaglandin synthesis

14

% of platelets in circulation

70%

15

% of platelets in spleen

17%

16

% of platelets in liver, lungs, bone marrow

13%

17

Platelet factor

substance absorbed onto the plt membrane or carried in the plt granules that are released during the release reaction and that influence homeostasis

18

PF1

absorbed coagulation factor V

19

PF2

fibrinogen activating factor

20

PF3

platelet phospholipid
acts as organization surface to bring required factors into close proximity and facilitate reaction

21

PF4

anti-heparin factor
glycoprotein that inhibits the reaction of heparin

22

Platelet functions (2)

hemostatic functions (plug, adhesion, aggregation and retraction)
Thromboplastic (actual clot, plt releases chemicals that reinforce vasoconstriction, aggregation and coagulation reactions that promote growth and healing)

23

platelet adhesion requires (2)

GPIb
vwF

24

Primary aggregation requires (4) - reversible

ADP
GIIb/IIIa
Ca2+
Fibrinogen

25

secondary aggregation requires (2) - irreversible

ADP and thrombin

26

Result of secondary aggregation (3)

induce prosaglandin synthesis
activate enzymes that hydrolyse plt membrane phospholipids
Arachidonic acid used by cyclooxyrgenase to produce PGH2 and then the enzyme TxA2 syntheses changes PGH2 into TxA2

27

Thromboxane A2 functions (3)

release calcium
lowers camp levels
vasoconstrictor

28

Contractile protein involved in plt retraction

Thrombosthenin

29

Inhibitors of plt aggregation will increase CAMP levels by

activating adenylcyclase or inhibiting phosphodiesterase

30

Aggregation agents will decrease CAMP levels by

inhibiting adenycyclase or activating phosphodiesterase

31

Chelating agents inhibit plt aggregation by

removing Ca2+

32

Heparin inhibits

thrombin

33

Aspirin inhibits plt aggregation by

inhibiting TxA2 synthesis in plts

34

Screening test for plts (4)

plt count
bleeding time
closure time
capillary fragility

35

Function tests for plt adhesion, aggregation, retraction (5)

plt adhesion tests
plt aggregation tests
prothrombin consumption time
PF3 availability
clot retraction

36

Tests for cause of low plt (3)

bone marrow examination
tests for anti-plt antibody
Plt survival studies

37

All activated enzymes are _____ except XIIIa

serine proteases

38

XIIIa

transamidase

39

Factor that is never "activated"

I

40

Factor VIII made up of 2 components

antihemophilic
VWF

41

Contact group key words

His private parts hurt

HMWK, PTA, PK, Hageman

42

Prothrombin group key words

Presents save christmas Santa

Prothrombin, stuart-prower, christmas, stable

43

Fibrinogen group key words

Fancy ladies acquire funds

Fibrinogen, Labile, antihemophilic, fibrinase

44

Intrinsic group key words (APTT)

Horny prostitutes have coitus and spread legs for precious pennies

HMWK, Prothrombin, hageman, christmas, antihemophilic, stuart power, labile, fibrinogen, pta, pk

45

extrinsic group key words (PT)

Silly sluts love pillow fights

Stuart prower, stable, labile, prothrombin, fibrinogen

46

Factors key words

French I Fibrinogen
prostitutes II Prothrombin
tell III Tissue factor
clients IV Ca2+
loves V Labile
stupid VII Stable
anyways VIII Antihemophilic
children IX Christmas
spend X Stuart-prower
pennies XI PTA
hella XII Hageman
fast XIII Fibrinase

47

Thrombin major functions (4)

converts fibrinogen to fibrin
activates factor XIII
enhances factor V and VIII
induces plt aggregation

48

How does factor XIII stabilize fibrin clot

catalyzing formation of strong covalent bonds between amino acids of fibrin monomers in different polymers

49

Localization and control of hemostasis (5)

inhibition of hemostasis by products of coagulation
concentration of coagulation factors by their adoption onto plt surface
Natural antithrombins in plasma (pinocytosis)
Tissue damage starts fibrinolytic system
Thrombomodulin binds to thrombin and activates protein C (destroys V and VIII)

50

most significan antithrombin

antithrombin III
activated by heparin
Inhibits: II, VII, IX, X, XI, XII

51

2 ways plasminogen activated plasmin

tpa secreted by injury
weakly activated by thrombin
accelerated by XII, HMWK, PK

52

5 actions of plasmin

digest/destroy structure of fibrinogen/fibrin
produces FDP
destroys V, VIII, IX, XI
activates complement
enhances XII and PK

53

FDP roles (3)

inhibit thrombin
inhibit fibrin polymerization
increase vascular permeability

54

tests for fibrinolysis (2)

D Dimer (increased; secondary fibrinolysis)
Fibrinogen assay (decreased)

55

Groups consumed during coagulation

fibrinogen group
XI from contact group
II from prothrombin group

56

Groups present in serum (after clotting)

contact and prothrombin (except factor II)

57

groups Present in plasma

contact, prothrombin and fibrinogen (except I, XIII)

58

Groups absorbed by BaSO4

prothrombin group

59

Groups Present in absorbed plasma

contact and fibrinogen

60

Groups dependent on Vit K

Prothrombin

61

Groups synthesized in liver

Prothrombin and fibrinogen (except VIII)