Coagulation Cascade - Brar Flashcards

1
Q

What are the 4 major players in forming a clot?

A
  1. Endothelial Cells
  2. Subendothelial Cells
  3. Platelets
  4. Clotting factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Endothelial cells have what affect on blood clotting?

A

Inhits it

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

Endothelial cells inhibit blood clotting by forming what, which inhibits platelet adhesion & aggregation?

A

Prostacyclin

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

Platelets release what after they bind to subendothelial tissue?

A
  1. Protiens

2. Vasoactive amines

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

Plasma protiens which create a proteolytic cascade which ends with the production of insoluble firbrin from soluble fibrinogen are called what?

A

Clotting factors

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

What mediates platelet adhesion to exposed extracellular matrix when the endothelial lining of blood vessel is damaged?

A

von Willebrand Factor (vWF)

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

vWF is a protein that is present where?

A
  1. Plasma

2. Extra cellular matrix

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

vWF binds to what?

A
  1. A receptor on the platelet membrane

2. Collagen fibers in the tissue

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

Adhered platelets by agents that increase the calcium concentration of platelets, which is typically what 2 agents?

A
  1. Thrombin

2. Thromboxane

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

During activation, a receptor for what becomes exposed on the platelet membrane?

A

Fibrinogen

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

Fibrinogen binds to a receptor exposed on the platelet membrane and causes what?

A

Platelet aggregation

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

Fibrinogen consists of how many pairs of polypeptides?

A

3

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

Fibrinogen is the precursor for what?

A

Fibrin

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

What converts fibrinogen into fibrin?

A

Protease thrombin

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

Why is fibrinogen more soluble than fibrin?

A

The fibropeptides are covered in negatively charged aspartate & glutamate residues (repel eachother)

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

The negative charges on fibrinopeptides help prevent what?

A

Aggregation

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

The crosslinking of fibrin is catalyzed by what?

A

Transglutaminase (factor XIII)

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

Thrombin formation is limited to where?

A

The site of injury

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

Thrombin is produced from prothrombin vi what?

A

Factor X a

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

The formation of Thrombin produces what other product?

A

A catalytically inactive fragment

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

The catalytically inactive fragment produced with thrombin has 10 residues of what?

A

Gamma- carboxyglutamate

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

Gamma- carboxyglutamates are produced by hepatocytes in a reaction requiring what?

A

Vitamin K

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

What is the only protease in the extrinsic pathway?

A

Factor VII a

24
Q

Factor VIIa is only active in the presence what?

A

Tissue factor

25
Q

Tissue factor is a membrane glycoprotein exposed after what?

A

Injury of the blood vessel

26
Q

The intrinsic pathway requires what to activate?

A

a negatively charged surface (ex. glass or phospholipid membrane)

27
Q

What are the initiating reactions of the intrinsic pathway?

A

Contact phase activation

28
Q

The contact phase activation requires what two proteases?

A
  1. Kallikrein

2. Factor XIIa

29
Q

The contact phase activation requires which activator protein?

A

High Molecular Weight Kininogen (HMWK)

30
Q

Factor IXa activates Factor X, this step requires what?

A

Factor VIIIa

31
Q

Which clotting factors are vitamin K dependent?

A
  1. Prothrombin (II)
  2. Factor X
  3. Factor VII
  4. Factor IX
32
Q

Which factors are Heparin inhibited?

A
  1. II (prothrombin)
  2. X
  3. IX
  4. XI
  5. XII
33
Q

What is the most important protease inhibitor that inactivates the clotting factors?

A

Antithrombin III

34
Q

Antithrombin III is activated by what?

A

Heparin

35
Q

Thrombomodulin is found on the surface of endothelial cells, it binds to what?

A

Circulating thrombin

36
Q

What does protein C degrade?

A
  1. Factor V a

2. Factor VIII a

37
Q

Thrombomodulin is present only on what?

A

intact endothelium

38
Q

Plasmin degrades what?

A

The fibrin clot

39
Q

Active plasmin is formed only where?

A

in the fibrin clot where it is needed

40
Q

The fibrin complex can be activated by what?

A

Tissue type plasminogen activator (tPA)

41
Q

tPA (tissue type plasminogen activator) is what type of protease?

A

Serine

42
Q

Plasminogen can also be activated by what?

A
  1. Urokinase

2. Streptokinase

43
Q

tPA can be used in the event of what?

A

Acute MI (if administered within an hour, very risky)

44
Q

Clotting can be inhibited by removing what?

A

Calcium ions

45
Q

Which factors of the clotting cascade depend on calcium?

A

All gamma-carboxyglutamate containing factors

46
Q

Which factors contain gamma-carboxyglutamate?

A
  1. prothrombin
  2. VII
  3. IX
  4. X
47
Q

Bleeding time is prolonged in what?

A

Platelet deficiencies

48
Q

Activated partial thromboplastin time (PTT) is used to measure what?

A

Efficacy of Heparin

49
Q

PTT tests which pathways?

A
  1. Intrinsic Pathway

2. final common pathway

50
Q

Prothrombin time is prolonged in deficiencies of which pathways?

A
  1. Extrinsic pathway

2. Final common pathway

51
Q

PT is used routinely to measure what therapy?

A

Coumadin

52
Q

Hemophilia A is the result of a deficiency in what?

A

Factor VIII

53
Q

Hemophilia B is a result of a deficiency in what?

A

Factor IX

54
Q

Hemophilia has what inheritance pattern?

A

X-linked (Almost exclusively found in males)

55
Q

What is the only effective therapy for hemophilia?

A

Injections of Factor VIII