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Flashcards in Quiz 1 Deck (31):
1

What are the five stages of hemostasis?

  1. Vasoconstriction 
  2. Formation of platelet plug 
  3. Activation of clotting cascade 
  4. Formation of Fibrin clot 
  5. Clot Retraction and dissolution 

2

What does the coagulation system do?

Forms a clot at an injured or inflamed site. 

Also, 

Prevents infection, stops bleeding, and provides framework for repair and healing. 

3

What is the coagulation system composed of?

A platelet plug and crossed think mesh of protein called fibrin

4

When there is no side of injury what happends in the vessel?

The inside of the vessel activily repells clotting. 

Actively anti-clotting 

5

What do platelets look like?

What is there function?

How are they formed?

  • Disk Shaped cytoplasmic fragements-no nucleus 
  • Essential for coagulation and control bleeding 
  • Formed by fragmentation of megkaryocyte precursors 

6

Megkaryokyte to----->?

Platelet 

7

What is hematopoiesis?

Is the process of blood cell formation 

Occurs in the bone marrow after birth 

8

What are the 2 stages in hematopoietic development?

Proliferation of precursor cells 

Differentiation of precursor cells 

9

Talk through the development of Platelets

What is this process called?

First starting for a megakaryocyte, the cell undergoes the nuclear phase of cell division, 

But does not undergo cytoplamic division 

The megakaryocyte expands due to DNA doubling, then they are broken into fragments. 

 

Endomitosis

 

10

Platelets or thromombocytes are what?

membran bound fragments of megakaryocyte cytoplasm 

11

Production and differentiation of megakaryocytes are regulated by Thrombopoietic growths factors:? 

Thrombopoietin 

Interleukin-11

12

Platelets are destroyed in the?

Spleen 

13

True or False 

Platelet function and count corelates to their function?

False 

14

What is a normal Platelet count?

140,000- 340,000/mm3

15

ThromboCYTHEMIA count

greater than 600,000/mm3

 

16

Thrombocytopenia count

less than 100,000

17

Immune thrombocytopenic purpura (ITP) what occurs and how is it mediated?

Antibody mediated distruction of platelets 

18

How is ITP treated?

glucocorticosteriods 

Thrombopoietin receptor agonists 

19

Hemostasis has 3 parts 

Activation of platelets (primary)

Activation of coagulation factors (secondary)

Activation of the fibrinolytic system 

20

In what step is the fibrin clot and activation of clotting cascade?

2 secondary hemostasis 

Activation of coagulation factor 

21

In hemostasis I, what occurs? What is it also called?

It is called primary hemostasis 

Vasoconstriction and formation of a platelet plug 

22

In an uninjured blood vessel what stops the clotting and platelet activation?

Antiplatelet activities release mediators which inhibit the activation of platelets

 

Antithrombic activities inhibit the clotting cascade

Fibrinolytic activities breakdown clots 

23

What does dipyridamole do?

increases the cellular concentration of cAMP/cGMP

This prevents platelet activation 

24

Aspirin blocks what?

COX 1 its a really good inhibitor 

Causing degranulation 

25

Clopidogrel blocks?

P2y12

 

Causing degranulation 

26

Platelets activation by the clotting cascade is activated by?

Thrombin 

27

What is thrombin formed by and what does it do?

What does it lead to?

Formed by coagulation cascade and it binds to Protease Activated Platelet receptors PAR1 and PAR2 

 

Aggregation and activation of platelets 

28

Four factors secreted by platelets? During platelet degranulation 

  1. ADP activates P2Y1 and P2Y12, this promotes platelet aggregation and secretion 
  2. Thromboxane A2 (TXA) made via COX1 promotes platelet aggregation and vasoconstriction 
  3. Serotonin(5-HT) promotes vasoconstriction 
  4. PDGF (platelet-derived growth factor) 
    1. Chemotactic, mitogenic
    2. Stimulated wound healing 

29

Platelet plugs dont form without what?

What drugs block this?

Fibrinogen

 

Abciximab, eptifibatide, tirofiban 

30

What complex is extremely important for platelet aggregation?

The GPIIb-IIIa fibrinogen complex 

 

This is a dope ass drug target

31

Platelets do what to increase efficacy?

Change shape to increase surface area