Hematology Exam 6 Flashcards

1
Q

Vascular integrity and platelets forming a primary, temporary plug are a part of ________ coagulation.

A

Primary coagulation

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2
Q

Plasma coagulation factors are a part of _________ coagulation

A

Secondary coagulation

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3
Q

Blood fluidity is dependent on the fibrin lysing system and _______ to coagulation in order to prevent excess clot formation

A

Inhibitors

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4
Q

What are the other names for Factor III?

A
  • Tissue factor
  • Tissue thromboplastin
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5
Q

Rare condition producing abnormal connective tissue and poor support

A

Telangiectasia

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6
Q

Is telangiectasia an inherited or acquired vascular disorder?

A

Inherited

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7
Q

Type of vascular disorders that may damage endothelial cells or connective tissue

A

Acquired vascular disorders

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8
Q

Blood pressure cuff at 80mmHg for 5 minutes then taken off to count petechiae present in a 3 square centimeter area

A

Tourniquet test

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9
Q

Normal platelet range

A

150,000-450,000/mm3

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10
Q

What percentage of platelets are reserved in the spleen?

A

33%

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11
Q

Maturation of megakaryocytes include what 3 stages?

A
  • Megakaryoblast
  • Promegakaryocyte
  • Megakaryocyte
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12
Q

What influences the multi-potential stem cell to produce megakaryocytes?

A

CSF-MEG and thrombopoietin

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13
Q

66% of platelets cirtculate how many days before the spleen destroys them?

A

5-10 days

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14
Q

New terminology for the peripheral zone of a platelet

A

Platelet plasma membrane

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15
Q

New terminology for the structural zone of a platelet

A

Platelet cytoskeleton

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16
Q

What is the bilayer plasma membrane of a platelet composed of?

A

-Phospholipids and cholesterol

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17
Q

Purpose of cholesterol in the bilayer of the plasma membrane of a platelet

A

Stability, fluidity, transmembranous passageway

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18
Q

What is the fluffy outer coat that contains factors for adhesion and aggregation on platelets known as?

A

Glycocalyx

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19
Q

Glycoprotein that allow platelet to adhere to collagen

A

GP Ia/IIa

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20
Q

Glycoprotein that allows platelet to bind to vWF

A

GP Ib/IX/V

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21
Q

Glycoprotein that allows binding of fibrinogen to vWF

A

GP IIb/IIIa

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22
Q

Part of the platelet that acts as a barrier and regulates metabolic function

A

Plasma membrane

(aka Peripheral zone)

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23
Q

This section of the platelet is where the “inside/outside” response occurs

A

Platelet cytoskeleton

(aka structural zone)

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24
Q

What are the mcirofilaments in the platelet cytoskeleton composed of?

A

Actin

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25
Q

Purpose of actin in the platelet cytoskeleton

A

Anchors the plasma membrane glycoproteins

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26
Q

Section of the platelet that enables it to store additional quantities of hemostatic proteins found in the glycocalyx

A

Surface Connected Canalicular System (SCCS)

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27
Q

This part of the platelet sequesters calcium and bears enzymes that support platelet activation

A

Dense tubular system

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28
Q

Enzymes found in the dense tubular system (3)

A
  • Cyclooxygenase
  • Thromboxane synthetase
  • Phospholipase A2
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29
Q

What section of the platelet is known as the control center for platelet activation?

A

Dense tubular system

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30
Q

What are the 2 major types of granules in platelets?

A
  • Dense
  • Alpha
31
Q

Which platelet granules contains ADP, ATP and Ca2+?

A

Dense granules

32
Q

These platelet granules contain Factor V, Fibrinogen, vWF, and plasma coagulation activation factors such as HMWK

A

Alpha granules

33
Q

Which platelet granules will migrate to the plasma membrane and release their contents directly into plasma upon activation?

A

Dense granules

34
Q

Alpha platelet granules will fuse to which part of a platelet when activated and release their contents?

A

SCCS (Surface connected cannalicular system)

35
Q

4 Main functions of platelets

A
  • Adhesion
  • Shape change
  • Aggregation
  • Secretion
36
Q

What stimulates the formation of thromboxane A2?

A

Arachidonic acid

37
Q

A platelet count below what number will cause spontaneous bleeding?

A

Less than or equal to 10,000/µL

38
Q

Which platelet test involves a shallow cut made on the forearm and then time is measured regarding the amount of time it takes for the site to stop bleeding when constant pressure in applied via a BP cuff at 40mmHg?

A

Bleeding time

39
Q

Examples of primary disorders that cause a quantitative defect resulting in a high platelet count (4)

A

Myeloproliferative disorders such as:

  • Polycythemia vera
  • Chronic myeolcytic leukemia
  • Myelofibrosis with myeloid metaplasia
  • Essential thrombocythemia
40
Q

Examples of secondary disorders that cause a quantitative defect resulting in a high platelet count (3)

A
  • Inflammation
  • Iron deficiency
  • Acute blood loss
41
Q

Aplastic anemia, megaloblastic anemia, marrow infiltraion by malignant cells, and chemotherapy would all cause quantitative platelet defects resulting is ___________ (low/high) platelet counts.

A

LOW platelet counts

42
Q
  • Increased platelet destruction due to an autoantibody to platelets
  • Fairly common
  • May be acute or chronic
  • Acute is seen in children following infection
  • Chronic is often seen in women of child-bearing years
A

Idiopathic Thrombocytopenia Purpura (ITP)

43
Q

Quantitative platelet defect:

  • Ages 2-6 years
  • Platelet count <20,000/uL
  • Petechiae are common
  • Following a viral infection such as rubella, chickenpox, CoV-19
  • Antibody produced against viral antigens bind to the platelet surgace causing destruction of platelet
A

Acute ITP

44
Q

TRUE or FALSE:

Acute ITP is typically self-limiting and will resolve itself

A

TRUE

45
Q

Quantitative platelet defect:

  • Ages 20-40 years old
  • Onset is gradual
  • Platelet count 30,000-80,000/uL
  • More common in females
A

Chronic ITP

46
Q

Heparin and quinidine are drugs that cause increased platelet destruction due to actings like ______ which eleicit an antibody response

(Think immunology)

A

Haptens

47
Q

Platelets contain more of which major type of granule?

A

Alpha granules (50-80 per platelet)

48
Q

Which glycoprotein will vWF bind to on a platelets surface to make the platelet adhere reversibly to the vessel wall?

A

Glycoprotein Ib

49
Q

Exposure to collagen and ADP being secreted will cause platelets to do what?

A

Platelets will change shape from discoid to a spiny sphere with pseudopods

50
Q

For platelet aggregation, what glycoprotein will fibrinogen bind to?

A

Glycoprotein IIb-IIIa

51
Q

What is produced during secondary aggregation?

A

An irreversible plug

52
Q

What is produced by plasma clotting factors in order to reinforce the irreversible platelet plug to stop bleeding?

A

Fibrin

53
Q

3 different platelet tests

A
  • Platelet count
  • Bleeding time
  • Platelet aggregation
54
Q

Which platelet test checks platelet count as well as vascular integrity?

A

Bleeding time

55
Q

What are the commonly usecd aggregating agents in platelet aggregation studies?

A

Epinephrine, ADP, Collagen, and Ristocetin

56
Q

Antibodies produced against viral antigens (chickenpox, rubells, etc.) bind to the platelet surface causing the platelet to be destroyed

A

Acute ITP

57
Q

What 2 drugs act as haptens and elicit an antibody response creating an antigen-antibody complex that attaches to the platelet surface causing the platelet to be removed from circulation?

A

Heparin and Quinidine

58
Q

What are the 3 most common causees of increaased platelet destruction due to non-immune destruction?

A
  • Thrombotic Thrombocytopenic Purpura (TTP)
  • Hemolytic Uremic Syndrome (HUS)
  • Disseminated Intravascular Coagulation (DIC)
59
Q

Best way to tell the difference between ITP and TTP?

A

Neurological symptoms are seen with TTP and not with ITP

60
Q

How is TTP treated?

A

Plasma exchange

  • Remove ULVWF
  • Replace with fresh frozen plasma (FFP) or cryoprecipitate poor plasma

As well as corticosteroids

61
Q

Which platelet disorder is missing ADAMTS-13?

A

Thrombotic thrombocytopenic purpura

62
Q

Purpose of ADAMTS-13

A

Cleaves the ULVWF (ultra-large vonWillebrand Factor) multimers into smaller vWF multimers

63
Q

In the absence of ADAMTS-13, ULVWF will bind to which platelet glycoproteins?

A

GP Ib and GP IIb/IIIa

64
Q

ULVWF binding to GP Ib and GP IIb/IIIa causes (increased/decreased) adhesion and aggregation which forms hyaline thrombi

A

Increased

65
Q

Name the platelet disorder:

  • Decreased platelet count
  • Schistocytes seen on PB smear
  • Decreased haptoglobin
  • Increased LDH and Bilirubin
  • Normal PT, PTT, Fibrinogen, FSPs, and D-Dimer
A

TTP

66
Q

This is found only in children following an infection, typically with either Salmonella or E coli.

A

HUS
Hemolytic Uremic Syndrome

67
Q

How are HUS and TTP differentiated?

A

TTP has neurologic symptoms as well as usually having a more severe thrombocytopenia
In HUS the platelet consumption is usually occurring in the kidneys

68
Q

Clotting occurs throughout the whole body.
Increased PT, PTT, FSP, and D-Dimer
Decreased platelet count and Fibrinogen

A

DIC
Disseminated Intravascular Coagulation

69
Q

Types of qualtitative platelet defects (3)

A
  • Adhesion
  • Aggregation
  • Secretion
70
Q

Most common adhesion defects (2)

A
  • Von Willebrand’s Disease
  • Bernard-Soulier Disease
71
Q

Defective glycoprotein Ib causing an inability to bind to vWF. Patients exhibit hemorrhage characteristics (expanding large hematomas)

A

Bernard-Soulier Disease

72
Q

Low, absent, or defective VIII:vWF causing defective platelet adhesion

A

Von Willebrand’s Disease

73
Q

Aggregation platelet defect due to a defective glycoprotein IIb/IIIa. Causes aa inability to bind fibrinogen and form bridges for aggregation

A

Glanzmann’s