Graham Hemostasis 2012 / Exam 2

Question 1

Hemostasis

Answer 1

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

Question 2

Four systems of hemostasis ?

Answer 2

• Vascular
• Platelets–Primary Hemostasis
• Coagulation–Secondary Hemostasis
• Fibrinolysis

Question 3

What metabolite induces Vasoconstriction ?

Answer 3

Serotonin and thromboxane A2

Question 4

What metabolite induces Vasodilation ?

Answer 4

Prostacyclin PG I2

Question 5

Name the 7 step of the Hemostatic Plug cascade ?

Answer 5

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

Question 6

Name the 5 step of the Platelet Function cascade ?

Answer 6

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

Question 7

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 ?

Answer 7

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

Question 8

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

Answer 8

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

Question 9

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 ?

Answer 9

• Glycoprotein (GP Ib)

* Von Willebrand factor

Question 10

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

Answer 10

• GP IIB
• GP IIIa
• Fibrinogen

Question 11

Recite the sequence of the Prostaglandin pathway?

Answer 11

Membrane Phospholipid 
           ↓
Arachidonic Acid 
           ↓
Prostaglandin Endoperoxides 
   ↓                                  ↓
PG12            Thromboxane A2

Question 12

Membrane Phospholipid is the substrate for what ?

Answer 12

Phospholipase A

Question 13

Arachidonic Acid is the substrate for what ?

Answer 13

Cyclooxygenase

Question 14

Prostaglandin Endoperoxides are the substrates for what ?

Answer 14

Prostacyclin Synthetase
&
Thromboxane Synthetase

Question 15

What INHIBITS platelet aggregation ?

Answer 15

PG 12

Question 16

What INDUCES platelet aggregation ?

Answer 16

Thromboxane A2

Question 17

2 Primary Hemostatic Disorders?

Answer 17

• Inherited = in the young

* Acquired = Most problematic

Question 18

Without the Prostaglandin Pathway, the platelets . . . .

Answer 18

Will not work

Question 19

4 Inherited Platelet Disorders

Answer 19

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

Question 20

What is the most common platelet disorder?

Answer 20

von Willebrand Disease

Question 21

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

Answer 21

Glanzmann’s Thrombasthenia

Give platelets.

Question 22

Bernard Soulier Disease

lacks what ?

Answer 22

Protein 1b which is necessary for adhesion.

Question 23

4 Acquired Platelet Disorders ?

Answer 23

DRUGS: Ibuprofen
Uremia
Myeloproliferative Disorders

Question 24

Myeloproliferative Disorders

Answer 24

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

Question 25

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

Answer 25

Cyclooxygenase

Question 26

* Screening test for primary hemostasis * Not a good predictor of surgical bleeding risk * Very technique-dependent

Answer 26

Bleeding Time

Question 27

Platelet Function Analyzer (PFA)

Answer 27

is the modern “In vitro bleeding time”

Question 28

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

Answer 28

Platelet Aggregation Studies

Question 29

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

Answer 29

Platelet number Platelet function Vascular integrity

Question 30

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

Answer 30

* Platelet number * Platelet function * vWD * NSAIDS

Question 31

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?

Answer 31

* Collagen/Epinephrine | * Collagen/ADP

Question 32

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

Answer 32

adhesion, activation, and aggregation can be evaluated.

Question 33

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

Answer 33

94 - 194 sec

Question 34

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

Answer 34

* Intrinsic platelet defects, * vWD, or * platelet inhibiting agents

Question 35

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

Answer 35

intrinsic platelet defect or vWF

Question 36

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

Answer 36

71 - 118 sec

Question 37

Cascade system activated by substances released at the time of injury

Answer 37

Coagulation--Secondary Hemostasis

Question 38

Coagulation Factor X III =

Answer 38

Fibrin Stabilizing Factor Factor XIII deficiency causes hemophilia A

Question 39

During Intrinsic pathway, XII + Surface contact =

Answer 39

XIIa

Question 40

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 ?

Answer 40

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

Question 41

In the Common Pathway, | Xa + (Va, phospholipids, & Calcium) =

Answer 41

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

Question 42

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

Answer 42

Long strands of Fibrin

Question 43

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

Answer 43

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