Graham Hemostasis 2012 / Exam 2 Flashcards Preview

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Flashcards in Graham Hemostasis 2012 / Exam 2 Deck (43)
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1
Q

Hemostasis

A

The property of circulation whereby blood is maintained as a fluid within the vessels

2
Q

Four systems of hemostasis ?

A
  • Vascular
  • Platelets–Primary Hemostasis
  • Coagulation–Secondary Hemostasis
  • Fibrinolysis
3
Q

What metabolite induces Vasoconstriction ?

A

Serotonin and thromboxane A2

4
Q

What metabolite induces Vasodilation ?

A

Prostacyclin PG I2

5
Q

Name the 7 step of the Hemostatic Plug cascade ?

A
  1. ) Vascular Injury
  2. ) Tissue Exposure
  3. ) Adhesion
  4. ) Aggregation
  5. ) Plug Formation
  6. ) Fibrin Formation
  7. ) Clot Retraction
6
Q

Name the 5 step of the Platelet Function cascade ?

A
  1. ) Circulating platelets; endothelial damage occurs.
  2. ) Platelet Adhesion
  3. ) Platelet Aggregation
  4. ) Plug Formation
  5. ) Fibrin Formation
  6. ) Clot retraction
7
Q

Platelets may become activated by any of several physiologic or pathologic acivators released or exposed a the site of injury. Name 8 of theses activators ?

A
  • Collagen
  • Thrombin
  • Adenosine Diphosphate (ADP)
  • TXA2
  • Epinephrine
  • Serotonin
  • Arginine Vasopressin (AVP or ADH)
  • Platelet Activating Factor ( PAF)
8
Q

Platelet activators are counterbalanced by the presence of several inhibitors of activation which include what ?

A
  • Flowing Blood
  • Endothelial products
  • Prostacyclin (PgI2) &
  • Nitric Oxide
9
Q

Injury (or disease) of the vessel endothelium exposes a number of adhesive subendothelial proteins which promotes formation of a platelet plug which adheres to the exposed sub-endothelium. Name the 2 main components ?

A
  • Glycoprotein (GP Ib)

* Von Willebrand factor

10
Q

During Aggregation, platelets adhere to each other to form a plug. Adherent platelets release dense bodies and alpha granules, name the 3 main components ?

A
  • GP IIB
  • GP IIIa
  • Fibrinogen
11
Q

Recite the sequence of the Prostaglandin pathway?

A
Membrane Phospholipid 
           ↓
Arachidonic Acid 
           ↓
Prostaglandin Endoperoxides 
   ↓                                  ↓
PG12            Thromboxane A2
12
Q

Membrane Phospholipid is the substrate for what ?

A

Phospholipase A

13
Q

Arachidonic Acid is the substrate for what ?

A

Cyclooxygenase

14
Q

Prostaglandin Endoperoxides are the substrates for what ?

A

Prostacyclin Synthetase
&
Thromboxane Synthetase

15
Q

What INHIBITS platelet aggregation ?

A

PG 12

16
Q

What INDUCES platelet aggregation ?

A

Thromboxane A2

17
Q

2 Primary Hemostatic Disorders?

A
  • Inherited = in the young

* Acquired = Most problematic

18
Q

Without the Prostaglandin Pathway, the platelets . . . .

A

Will not work

19
Q

4 Inherited Platelet Disorders

A
  • von Willebrand Disease
  • Glanzmann’s Thrombasthenia
  • Bernard Soulier Disease
  • Deficient Release Reaction
20
Q

What is the most common platelet disorder?

A

von Willebrand Disease

21
Q

What disorder lacks GP IIB
GP IIIa ?
How would you treat this ?

A

Glanzmann’s Thrombasthenia

Give platelets.

22
Q

Bernard Soulier Disease

lacks what ?

A

Protein 1b which is necessary for adhesion.

23
Q

4 Acquired Platelet Disorders ?

A

DRUGS: Ibuprofen
Uremia
Myeloproliferative Disorders

24
Q

Myeloproliferative Disorders

A

Chronic leukemia’s that effects the platelets that the body produces

25
Q

Aspirin has a blocking effect on what portion of the prostaglandin pathway ?

A

Cyclooxygenase

26
Q
  • Screening test for primary hemostasis
  • Not a good predictor of surgical bleeding risk
  • Very technique-dependent
A

Bleeding Time

27
Q

Platelet Function Analyzer (PFA)

A

is the modern “In vitro bleeding time”

28
Q

How can we look at individual affects of different activators on platelets? What test should we order?

A

Platelet Aggregation Studies

29
Q

Platelet Function Analysis via a bleeding time study would provide what information ?

A

Platelet number
Platelet function
Vascular integrity

30
Q

Platelet Function Screen via a Platelet Function Analyzer (PFA) study would provide what information ?

A
  • Platelet number
  • Platelet function
  • vWD
  • NSAIDS
31
Q

With the (PFA 100 Principle) Citrated whole blood is aspirated through a capillary towards a membrane that is coated with what agonists that activate platelets?

A
  • Collagen/Epinephrine

* Collagen/ADP

32
Q

Agonists in combination with high shear stresses create an environment where . . .

A

adhesion, activation, and aggregation can be evaluated.

33
Q

During a PFA interpretation what are the normal values for collagen/Epinephrine ?

A

94 - 194 sec

34
Q

Abnormal values for Collagen/Epinephrine would indicate what possible platelet disorders?

A
  • Intrinsic platelet defects,
  • vWD, or
  • platelet inhibiting agents
35
Q

Abnormal values for Collagen/ADP would indicate what possible platelet disorders?

A

intrinsic platelet defect or vWF

36
Q

During a PFA interpretation what are the normal values for Collagen/ADP ?

A

71 - 118 sec

37
Q

Cascade system activated by substances released at the time of injury

A

Coagulation–Secondary Hemostasis

38
Q

Coagulation Factor X III =

A

Fibrin Stabilizing Factor

Factor XIII deficiency causes hemophilia A

39
Q

During Intrinsic pathway, XII + Surface contact =

A

XIIa

40
Q

Extrinsic pathway begins with the release of an intracellular lipoprotein, tissue thromboblastin (FACTOR III) by vascular injury outside the vessel. In the presence of Calcium, tissue thromboplastin activates what ?

A

VII
The thromboblastin factor VIIa complex then activates factor X from the common pathway & factor IX from the intrinsic pathway.

41
Q

In the Common Pathway,

Xa + (Va, phospholipids, & Calcium) =

A

Prothrombin activator complex which activates prothrombin (Factor II) to Thrombin

42
Q

In the Common Pathway, Thrombin + Fibrinogen (I) =

A

Long strands of Fibrin

43
Q

In the Common Pathway, Thrombin also activates what other factors?

A

Factor XIII (fibrin stabilizing factor)
Factor XIIIa &
Calcium
forming an insoluble meshwork that is incorporated into the platelet plug.