Exam 1 Material Flashcards
This is the site of Prostaglandin and thromboxane synthesis:
Dense Tubular System in the Organelle Zone
What are the 5 steps of platelet plug formation:
1) Adhesion
2) Activation
3) Aggregation
4) Secretion
5) Stabilization of plt plug (fibrin)
What 3 components are involved in platelet adhesion:
- vWF
- GPIb
- Collagen fibers
A strong agonist will take platelet plug formation straight to this step:
Secondary aggregation
*which is permanent
What happens during plt activation:
- 2nd messenger pathway activated
- shape change
- Secrete granules
- Organelles move to center
Aggregation depends on the strength of the _____:
agonist
T/F Aggregation begins 10-20 seconds following injury/plt adhesion, and requires ATP from glycolysis:
True
List the 3 things required for aggregation:
- Ionized Calcium
- GPIIb/IIIa
- Fibrinogen
What initiates the intrinsic pathway:
Exposure to subendothelial collagen
What initiates the extrinsic pathway:
Release of tissue factor
What is secreted during platelet plug formation:
Alpha granules
Dense granules
lysosomes
prostaglandins
List 4 tests for plt activation:
- B-TG (beta thromboglobulin)
- PF4
- Thrombospondin
- PDGF
List some conditions associated with increased levels of plt activation markers:
arteriosclerosis, CVD, shock, DVT, DIC
Where is the glycocalyx located and what glycoproteins does it contain:
- Peripheral zone of plt
- GPIb
- GPIIb/IIIa
- GPVa
List the alpha granules:
PDGF vWF B-TG PF4 Fibronectin
What is the function of the alpha granules:
They are contact promoting factors
List the Dense granules:
ADP
ATP
Calcium
5-HT (serotonin)
What are the non-protein factor type granules:
Dense granules
Where is calcium sequestered, and when released triggers plt contraction:
Dense tubular system (organelle zone)
Where are peroxisomes found:
Organelle zone
Adhesion to aggregation takes ____:
10-20 seconds
This occurs when an external agonist interacts with a plt membrane receptor, a signal is transmitted form outer to inner cell, and 2nd messenger pathway is activated:
Plt Activation
Primary aggregation is _____, and secondary aggregation is _____:
Primary–> reversible
Secondary–> permanent
Plt count for Thrombocytopenia is:
<100,000/uL
At a plt count of _______ patients will show clinical signs/symptoms, at a plt count of ______, patients run risk of spontaneous hemorrhage:
<50,000/uL
<20,000/uL
List some acquired causes of thrombocytopenia due to decreased number of megakaryocytes:
chemo
radiation
alcoholism
chloramphenicol
List causes of thrombocytopenia due to disorders of distribution/dilution of plts in circulation:
- spleen pooling (enlarged spleen will hold >30% plts)
- hypothermia
- dilution in circulation
Snake venom, tissue injury, OB complications, neoplasms, intravascular hemolysis –> how do these contribute to thrombocytopenia:
destruction of plts
via combined consumption of plt/coag factors
This is one of the most common disorders causing severe isolated thrombocytopenia, and is diagnosed by exclusion:
ITP (idiopathic thrombocytic purpura)
ITP is caused by an ______ against ______:
autoantibody against plts
Bernard Soulier, vWD, and Hemophilia A all are affected in this phase of clot formation:
Adhesion
Glanzmann’s is affected in this phase of clot formation:
Aggregation
This clotting disorder is X-linked recessive:
Hemophilia A
Bernard Soulier and Glanzmann’s are both this type of inheritance:
Autosomal recessive
What type of inheritance is Type 1 vWD:
Autosomal dominant
Glanzmann’s is a deficiency of this:
GPIIb/IIIa complex
Bernard Soulier is a deficiency of this:
GPIb/IX complex
What is the deficiency is Hemophilia A:
Molecular absence or defect in F8:C
coagulant portion of F8
What is the defect in Type 3 vWD:
Absence of vWF multimers
Which clotting disorder would have giant platelets:
Bernard Soulier
Which two clotting disorders have abnormal APTT’s:
vWD
Hemophilia A
Which two clotting disorders have absent plt aggregation with ristocetin, and which can be corrected w/ normal plasma:
Bernard Soulier, vWD
*can correct vWD w/ normal plasma
Which clotting disorder has decreased Factor 8:C:
Hemophilia A
Which clotting disorder will have normal to decreased vWF:Ag:
vWD
What type of bleeding is seen with Glanzmanns:
mostly mucosal bleeding
Which clotting is treated with DDAVP or Humate P:
vWD
Which clotting disorder needs the patient to practice good dental care:
Glanzmann’s
The following treatments can help control bleeding in what clotting disorder: DDAVP Estrogen therapy Recombinant F 8a Plt transfusion
Bernard Soulier
This disorder requires prophylactic infusions of Factor 8 in children (the dose will be tailored to activity level/risk of injury):
Hemophilia A
Bernard Soulier has normal aggregation with all the agents EXCEPT:
ristocetin
same as vWD
Will F8:C be normal in Bernard Soulier:
Yes
it would only be abnormal in Hemophilia A
Storage pool deficiency (granule defect) are classified by ___ and ___:
granule analysis
plt morphology
Alpha:
decreased alpha granules
Normal dense granules
GRAY PLT SYNDROME
Alpha-Delta:
Decreased: alpha granules dense granules PF4 Beta-thromboglobulin PDGF
Delta:
Decreased: dense granules ATP ADP Ca Serotonin
What is the disorder with decreased alpha granule proteins and reduced PF3 activity:
Quebec Plt Syndrome
List the 4 storage pool deficiencies associated with other congenital abnormalities:
- Hermansky-Pudlak (albinism)
- Chediak-Higashi
- Wiskott-Aldrich
- TAR (missing radial bones)
Would plt aggregation tests be normal in storage pool deficiencies:
No
but PT/APTT/Plt ct would be normal
Genetic deficiency of cyclo-oxygenase will lead to deficiency of _______ generation:
Thromboxane
Without Thromboxane, plt aggregation tests are unresponsive to _____ as a stimulator:
arachidonic acid
What are the treatments for storage pool and secretion defects:
Plt transfusions Cryoprecipitate DDAVP RBC transfusions Avoidance of NSAID's
Deficiency of ______ leads to deficient conversion of membrane-associated arachidonic acid to Thromboxane A2:
Cyclo-oxygenase
Where is vWF stored:
alpha granules
endothelial cells
If plts fail to generate Thrombin, (which is rare) bleeding pattern will closely resemble ______, and the treatment will be:
Hemophilias
Plt transfusions
(abnormal PF3, prolonged PT)
This serves as a ligand between plts, endothelial cells, and other proteins such as fibronectin:
vWF
This is an important adhesive protein on chromosome 12:
vWF
Circulating vWF forms complex with ____ which protects it from _____:
Factor 8
protects it from degredation
Type 1 vWD makes up ___% of cases:
70%
It is important to distinguish vWD from these other two clotting disorders:
Hemophilia A
Bernard Soulier
What are the changes in F1 you’ll see in early/mild, moderate, and end stage liver disease:
Early/mild: increase F1
Mod/severe: F1 dysfunctional (coated with sialic acid)
End stage: VERY decreased F1
Liver disease results in reduced plt ____:
adhesion
List the Vitamin K dependant factors:
2, 7, 9, 10
Factor ___ activity is more specific for liver disease:
Factor V
- Not affected by diet
- Not vit K dependent
Common pathway factors:
1, 2, 5, 10
Extrinsic pathway factors:
7
Intrinsic pathway factors:
8, 9, 11, 12
Which test measures the Extrinsic pathway?
PT
Which test measures the intrinsic pathway:
APTT
What will PT/APTT results be in: Vascular disorder Quant plt disorder Qual plt disorder Factor deficiency
Vascular disorder: N
Quant plt disorder: N
Qual plt disorder: N
Factor deficiency: Abnormal
With vit K defect, which would be abnormal, PT or APTT:
APTT
If inhibitor is present, TT result would be:
Normal
What would result for TT be in DIC:
abnormal
Where is thrombopoietin produced:
liver
lesser degree–>spleen
Thrombopoietin is cleared from plasma by receptors on _____, in thrombocytopenia, clearance is ____ and plasma concentration of thrombopoietin is_____:
megakaryoctes
low
increased
Eczema, skin lesions,and immunodeficiency are associated with this congenital thrombocytopenic disorder:
Wiskott-Aldrich
Hermansky-Pudlak syndrome is a platelet deficiency of ____:
nonmetabolic ADP
This disorder will present with giant platelets, thrombocytopenia, and Dohle bodies:
May-Heggelin anomaly
This typically presents in mainly women aged 20-50, with mucosal bleeding, younger platelets in circulation contribute to to BT closer to normal:
ITP
This must be dx via exclusion:
ITP
Post transfusion purpura is typically caused be an alloantibody to ____:
P1A1 (also called HPA-1a)
How does HIV affect plt production:
Causes BM hypocellularity, and subsequent thrombocytopenia
This microangiopathic disorder can present with hemolytic anemia, renal dysfunction, and neuro abnormalities:
TTP
Renal dialysis is more commonly needed in which disorder, TTP or HUS:
HUS
What is the treatment for TTP:
plasma exchange
Is plasma exchange the main treatment for HUS:
No. treatment is supportive, involving dialysis, antihypertensives, blood transfusions, steroids, anticoagulants etc
Gestational thrombocytopenia shares features with ____, but may not be immune related:
ITP
____is required for the stabilization of the GPIIb/GPIIIA complex:
CalciumL
List the two plt membrane defect disorders:
Glanzmanns
Bernard Soulier
Associate estrogen therapy with this disorder:
Bernard Soulier
Deficiency of alpha granules leads to this appearance, associated with this disorder:
Gray plt syndrome
*Quebec plt disorder
What is deficient in Quebec plt disorder:
Alpha granules
PF3
Which disorder has oculotaneous albinism, and which has ocular albinism w/ gray hair:
Hermanski-Pudlak
Chediak-Higashi
Cyclo-oxygenase deficiency results in deficient conversion of ___ to ___:
arachidonic acid–>Thromboxane A2
vWF acts as a carrier protein for ____:
Factor 8
T/F
In normal individuals, plasma levels of Factor 8 closely correlate with plasma levels of ____:
vWF
GPIb/IX is the receptor for ___:
vWF
DDAVP stimulates release of:
vWF from endothelial cells
Will PF3 be normal in liver disease:
No
Which lymphoproliferative malignancies can cause both hypo/hypercoagulability:
Paraproteinemias
Decreased plasma levels of F8:C, vWF:Ag, and vWF activity, and abnormalities in vWF multimeric patterns:
Acquired vWD
Are the effects on plts reversible or irreversible with the use of aspirin? ibuprofen?
Aspirin: irreversible
Ibuprofen: reversible
This rare congenital connective tissue disorder is due to decreased or low quality collagen:
Osteogenesis imperfecta
This rare congenital connective tissue disorder is due to bleeding abnormalities of connective tissues:
Marfan’s
What is the main feature of Ehlers-Danlos syndrome:
hyper-elastic skin
Pseudooxanthoma elasticum afffects the elastic fibers of the ___ and ___, caused by increased ___ and ___ in elastic fibers:
skin & arteries
Calcium & minerals
This disorder is caused by increased permeability of blood vessels of the GI tract, causes chronic GI bleeds, and is associated with von Willebrands:
Angiodysplasia
Factitious primary purpura:
self induced trauma
List the 5 types of primary purpura:
Simple Mechanical Senile Factitious Schambergs
List the 5 types of secondary purpura:
Infectious Allergic Metabolic Psychogenic Secondary to dysproteinemia
Treatment for DIC:
heparin
What coag factor deficiences are possible in liver disease:
Vit K dependant factors (2,7,9,10, protein C & S)
*Will see change in F7 first, has shortest half life
Bleeding in uremia is due to problem with this stage of clot formation:
adhesion, leads to abnormal aggregation
EDTA elevates results for ___ and ___, and reduces factors __ and ____:
PT/APTT
5 and 8
Heparin has this affect on PT/APTT:
prolonged
The BT is _____ in conditions with dysfunctionl plts and in thrombocytopenia:
prolonged
Can BT distinguish coag factor deficiency or bleeding risk:
no
The Clotting time test measures factors of the ____ pathway:
intrinsic
What are the two reagents used for PT:
Thromboplastin
Calcium
What is the ref range for PT:
11.5-14 sec
What is the ref range for APTT:
20-45 sec
This is used to neutralize Heparin:
protamine sulfate
What is the specimen for Protamine sulfate testing:
PPP plt poor (citrated) plasma
Can protamine sulfate testing be used for LMWH:
No. only for unfractionated heparin.
A positive protamine sulfate test:
presence of fibrin threats
Negative protamine sulfate test:
opalescent appearance of plasma
no fibrin threads
Plt aggregation requires a conformation in the _____ complex in order to allow ____ to bind:
GPIIb/GPIIIa (and GPV)
fibrinogen
Plt adhesions begins in ___ seconds, aggregation in ____ seconds following vascular injury:
Adhesion: 1-2 seconds
Aggregation: 10-20 seconds
List the different types of receptors found on platelets:
ADP thrombin epinephrine collagen TXA2 serotonin
What is the phospholipid component of the plt, which moves to the outer surface when plt is activated, allowing for assembly of vit k dependent factors:
PF3
Which platelet factor inhibits heparin:
Pf4
Primary aggregation involves stimulation by agonist, resulting in ____, and is ____:
ADP
Reversible (unless agonist is STRONG)
Secondary aggregation involves _____ and is ____:
Granule content release
irreversible
Secondary aggregation is dependent on the ____ of the ADP release from primary aggregation:
strength/amount
Are megakaryocytes capable of synthesizing cyclo-oxygenase:
Yes
ADP binding to the plt membrane allows for _____ to be converted to _____:
Arachidonic acid to TXA2
Serotonin is a ____ aggregating agent, but _____ other aggregating agents:
weak
amplifies
Serotonin serves as an important _____ and potent stimulator of smooth muscle ___ production:
vasoconstrictor
PGI2
Coumadin/Warfarin are ______ antagonists:
vitamin K
What are PIVKA’s:
proteins induced by vitamin k absence/antangonists
vit k deficient patients exhibit decreased production of functional prothrombin proteins
What two factors are the last stable:
5 and 8:C
Extrinsic pathways is activated by release of:
Tissue factor
Plasmin is converted to plasminogen by this:
tPA
What is the mechanism of coag drugs that end in -aban:
Direct Factor Xa inhibitors
This drug is an ADP binding inhibitor:
Plavix
What drug inhibits synthesis of vit k dependent clotting factors:
warfarin/ ‘Coumadin’
