endothelial cells and platelets Flashcards

1
Q

endothelial cells are _____ regulators of hemostasis

A

central

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

endothelium maintains a balance between ____ and _____ activitities

A

anti- and pro- thrombotic activitities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

T or F… anticoagulent factors are expressed under normal conditions

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

T or F… pro-coagulant activites are acquired following injury

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

fibrinolysis: t-PA cleaves?

A

plasminogen into plasmin which cleaves fibrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what cleaves fibrin?

A

plasmin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

antiplatelet

A
  • intact endothelium prevents contact with ECM
  • prostacyclin (PGI2) and nitirc oxide are vasodilators and inhibit platelet adhesion and aggreagtion
  • adenosine diphophatase, which degrades ADP, inhibits platelet aggregation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

anticoagulant

A
  • heparin-like molecules: co-factors that allow antithrombin 3 to inactivate thrombin (factors9a and 10a)
  • thrombomodulin: binds thrombin > cleaves and activates protein C along with protein S > inactivates factors 10a and 13a
  • tissue factor pathway inhibitor (TFPI) inhibits tissue factor-factor 7a complex and factor 10a
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

prothrombotic properties of injured or activated endothelium

A

1) activation of platelets
2) von Willebrand factor (vWF)
- producued by endothelial cells
- bound to ECM
- binds to Gp1b on the surafce of platelets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

tissue factor is produced in response to TNF, IL-1, bacterial endotoxin. It activates and downregulates what?

A
  • activates coagulation

* downregulates thrombomodulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what limits fibrinolysis?

A

plasminogen activator inhibiot (PAIs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

clotting factors binding tofactors _____ and ____, augment theircatalytic activities

A

9a anad 10a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

are platelets cells?

A

NO! they are cellular fragments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

platelets are critical in ?

A

hemostasis; formation of hemostatic plug, recruit and concentrate coagulation factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

two types of platelet granules?

A

1) alpha granules

2) dense bodies (delta granules)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

alpha platelet granules express?

A

express P-selectin and contain fibrinogen, fibronectin, factors 10 and 13, platelet factor-4, PDGF,TGF-beta

17
Q

dense plateket bodies (delta granules) contain?

A

contain ADP and ATP, ionized calcium, histamine, serotonin, and epinephrine

18
Q

histamine and serotonin affect on blood vessels?

A

vasodilation

19
Q

epinephrine affect on blood vessels?

A

vasoconstriction

20
Q

4 processes of platelets?

A

1) platelet adhesion
2) activation
3) aggregation
4) platelet-endothelial interactions

21
Q

platelet adhesion initiates? is mediated through?

A
  • initiates clot formation

* mediated through vWF and glycoprotein Gp1b

22
Q

Platelet Activation

A

release of alpha granules and dense bodies (delta granules)

  • production of thromboxane A2
  • change in shape to increase surface area to bind to vWF
23
Q

1) Platelet aggreagation bridging interaction?
2) thrombin stabolizes
3) thrombin converts
4) are RBCs and WBCs present?

A

1) bridge in interactions between fibrinogen and Gp2b/3a receptors
2) thrombin stabilizes the platelet plug via activation of a protease-activated receptor (PAR)
3) thrombin converts fibrinogen to fibrin
4) RBCs and WBCs are also present

24
Q

protease-activtated receptor (PAR) is a ______ hemostatic plug

A

secondary

25
Q

platelet-endothelial interactions is a balance between opposing effects of

A

prostacyclin (PGI2) and thromboxane A2 (TxA2)

26
Q

prostacyclin (PGI2) and thromboxane A2 (TxA2) which one dominates?

A
  • prostacyclin (PGI2) = during normal vessels

* thromboxane A2 (TxA2) = during endothelial injury injury (and PGI2 decreases)

27
Q

prostacyclin (PGI2) affect on blood vessels?

A

vasodilator, inhibits platelet aggregation

28
Q

thromboxane A2 (TxA2) affect on blood vessels?

A

vasoconstrictor

29
Q

what is the ultimate goal of clinical inhibition of platelet aggregation?

A

to lower the risk of coronary thrombosis

30
Q

what are two common drugs used to clinically inhibition of platelet aggregation?

A

aspirin and plavix

31
Q

what is aspirins affect on platelet aggregation?

A

permanently blocks platelet formation of TxA2 (also used as profilactic for heart probs)

32
Q

what is plavixs affect on platelet aggregation? aka?

A

plavix (clopidogrel) is an ADP antagonist only

*(ADP is a platelets activator)

33
Q

proteins ___ and ___ work together to activate factos 5a and 8a?

A

C and S

34
Q

heparin-like molecules are co-factors that allowantithrombin 3 to inactivate?

A

thrombin, factor 9a and factor 10a

35
Q

prostacyclin (PGI2) and nitric oxide have what affect on blood vessels? inhibit what aspect of platelets?

A

vasodilators

*inhibit adhesion and aggregation