Hemostasis Flashcards

Coagulation

1
Q

What is hemostasis?

A

The process by which the body control bleeding and maintains blood in a fluid form.

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

Hemostasis is composed of? (4)

A
  • Vascular system (blood vessels)
  • Platelets
  • Coagulation (factors)
  • Fibrinolysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What activates the primary hemostasis system? What 2 functions are primarily involved?

A

Activated by small vessel damage. Vasoconstriction Platelet function

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

What activates the secondary hemostasis system? What 2 functions are mainly involved?

A

Activated by major trauma, surgery, or hemorrhage Coagulation proteins Enzymatic reactions

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

What is vasoconstriction?

A

ability of small vessels to contract which decreases the diameter of of blood vessels and decrease blood flow.

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

What do platelets do?

A

Form a platelet plug

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

Coagulation is is dependent on a series of _______ that take part in a series of ______ ______ resulting in the formation of ______.

A

Proteins enzymatic reactions Fibrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The secondary system also includes _______ which is clot _____ once the blood loss has stopped and the vessel repaired.

A

Fibrinolysis dissolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The vascular system prevents bleeding through? (3)

A

Vessel constriction Activation of PLTs Activation of coagulation system

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

The vessel wall contains Fibrous tissue consisting of?

A

Collagen and elastic fibers smooth muscle

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

An injured vessel exposes collagen which reacts with PLTs via ____ _____ _____

A

von WIllebrand factor

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

What is the life span of a PLT?

A

7 - 10 days

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

What stimulates PLT production?

A

Thrombopoietin

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

PLT parent cell is the _______ that undergoes ________.

A

Megakaryocyte Endomitosis

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

There are no significant # of PLTs in bone marrow, _____ in circulation, and _____ in spleen.

A

67% BM 33% Spleen

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

What are the 3 phases of PLT function?

A

Adhesion Amplification Aggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens during PLT adhesion? What is required? (2)

A

PLTs adhere to collagen and change shape (when they interact) Required: von Willebrand factor (vWF) and Glycoprotein 1b (GpIb) Secretion of PLT and clot activating substances.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens during Amplification? What helps this?

A

Secreted substances recruit more PLTs to aggregate. Thromboxane A2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens during Aggregation and what is used?

A

PLTs adhere to other PLTs Uses GpIIb and GpIIIa to adhere with oth. PLTs via plasma proteins such as fibrinogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

T/F: PLTs play and important roles in the formation of the primary PLT plug (primary hemostasis) as well and the coagulation cascade (secondary hemostasis)

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

PLTs serve as the site for?

A

Coagulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are coagulation factors?

A

Blood proteins that conclude with an insoluble fibrin clot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where are all coagulation factors produced? Which one is not produced here?

A

Liver EXCEPT factor VIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the two different pathways for clotting?

A

Extrinsic (Tissue factor pathway): Rapid response to tissue injury Intrinsic (Contact activation pathway): slower response, but quantitatively more significant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Factor I (Fibrinogen) is a substrate for? and a precursor for? Is the largest? What 2 forms is it converted to? Polymerized clot forms when exposed to _____.

A

Substrate for thrombin and a precursor for fibrin Largest molecular weight Insoluble (fibrin that forms clot) Soluble (soluble peptides cleaved from fibrinogen to make fibrin) Thrombin

26
Q

What us Factor II (prothrombin) converted to?

A

Converted to Thrombin IIa (activated), which cleaves fibrinogen)

27
Q

What us Factor II (prothrombin) activate?

A

Cofactors, protein C, and Factor XIII

28
Q

Factor III (thromboplastin) activates ____ ___ when blood is exposed to ____ ____.

A

Factor VII, tissue fluids

29
Q

What is Factor IV (ionized calcium) needed for?

A

Active form of calcium needed for activation of thromboplastin and conversion of prothrobin to thrombin

30
Q

Factor V (proaccelerin or labile factor) speeds up which process?

A

Transformation of prothrobrin to thrombin.

31
Q

What factor is consumed during clotting?

A

V

32
Q

20% of what factors are found on platelets?

A

V

33
Q

Which factor is nonexisitent?

A

VI

34
Q

What factor is activated by tissue thromboplastin and activates Factor X?

A

Factor VII (proconvectin or stable factor)

35
Q

What factor is needed for the cleavage of Factor X to Xa by IX?

A

Factor VIII (antihemophilic factor)

36
Q

What factor is deficient in hemophilia A?

A

Factor VIII (antihemophilic factor)

37
Q

What factor is a plasma thromboplastin component?

A

Factor IX

38
Q

What factor is deficient in hemophilia B

A

Factor IX

39
Q

What factor known as Stuart-Prower merges to form conversion of prothrombin to thrombin

A

Factor X

40
Q

What factor is independently activated by Russell’s Viper Venom.

A

Factor X

41
Q

What factor is essential to the intrinsic pathway, with a decreased frequency in the Jewish population, and bleeding tendencies vary?

A

Factor XI, a plasma thromboplastin antecedent

42
Q

Known as Hageman factor, it is an activated contact factor that is activated by collagen. A deficiency may cause a prolonged PTT but not a bleeding problem, with a tendency toward thrombosis.

A

Factor XII

43
Q

This is a firbrin stabilizing factor, stabilizes polymerized fibrin monomers in the initial clot when exposed to calcium.

A

Factor XIII

44
Q

What are the 3 receptors on PLTs?

A

GpIb, GpIIb, and GpIIIa

45
Q

This the surface contact factor activated by kallikrein.

A

High-molecular weight kininogen (HMWK) *Homework

46
Q

Known as Fletcher factor, this is a surface contact activator.

A

Pre-kallikrein

47
Q

Identify the process involved in the coagulation cascade from activation to stable clot formation? (4)

A
  1. Vessel injury activates common pathway 2. results/leads to formation of fibrin clot 3. factor XIII stabilizes fibrin clot 4. Thrombin feedback activation of V, VIII, and XI amplify process.
48
Q

What are Regulatory Inhibitors?

A

Soluble proteins that are natural anticoagulants

49
Q

Protease inhibitors (3)

A

Antithrombin Protein C / Protein S Tissue Factor Pathway Inhibitor (TFPI)

50
Q

What is the Fibrinolytic System?

A

System that dissolves blood clots

51
Q

Plasminogen is converted to plasmin which_____

A

breaks down fibrin clot into fibrin products

52
Q

What are the characteristics of inhibitors (3)

A

Block activated coagulation factors, so widespread coag not occur. Limit fibrinolysis and neutralize activated factors in circulation. Each has a specific role.

53
Q

PT measures which pathway?

A
  • Extrinsic pathway
54
Q

aPTT (activated Partial Thromboplastin Time) measures which pathway?

A

Intrinsic Pathway

55
Q

Abnormal PT/Normal PT

A

Factor VII defieciency (Extrinsic)

56
Q

Abnormal PTT/ Normal PT

A

Defieciency of Factors:

  • X
  • XI
  • VII
  • II
57
Q

Abnormal PTT and PT

A

Deficiency of Factors:

  • X
  • V
  • II
  • I
58
Q

What is in the Contact group?

A
  • PreKal
  • HMWK
  • XI
  • XII
59
Q

These factors are in the Prothrobin Group, and are Vitamin K dependent?

A
  • 1972
    • X
    • IX
    • VII
    • II
60
Q

What factor is common to all 3 pathways?

A

X

61
Q

What medications are used w/ abnormal PT?

What medications are used w/ abnormal aPTT?

A
  • Warfarin
  • Coumadin
  • Heparin