Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Hematology 2 > (P) Lesson 1: Introduction to Hemostasis and Megakaryopoiesis > Flashcards

(P) Lesson 1: Introduction to Hemostasis and Megakaryopoiesis Flashcards

1
Q
  • A complex biochemical process by which the body spontaneously stops bleeding (hemorrhage) upon injury and maintains blood in a fluid state within the vessel compartment.
A

Hemostasis

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

How does the body spontaneously stop bleeding or hemorrhage upon injury?

A
  • The body makes use of platelets and clotting factor to prevent the bleeding.

Several proteins can either control their reactions and other can control the clotting of blood itself.

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

Imbalances in hemostasis may result in what?

There are two (2) answers.

A
  1. Hemorrhage (purpura)
  2. Thrombosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  • Characterized by excessive bleeding
  • E.g. Thrombotic thrombocytopenic purpura, idiopathic thrombocytopenic purpura
A

Hemorrhage (purpura)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  • Characterized by excessive clotting
A

Thrombosis

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

What are the four (4) factors that make a person prone to these blood disorders?

A
  1. Low platelet count
  2. Dysfunctional platelets
  3. Clotting factor deficiency
  4. Auto-antibodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T or F: Low platelet count is a qualitative defect while dysfunctional platelets are a quantitative defect.

A

False

Low platelet count is a quantitative defect while dysfunctional platelets are qualitative defects.

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

What is the reference value of platelets?

A

150,000 to 400,000 µl

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

This is a disorder associated with dysfunctional platelets and is characterized by impaired platelet aggregation.

A

Glanzmann’s thrombasthenia

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

What clotting factor is deficient in Hemophilia A?

A

Factor 8

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

What clotting factor is deficient in Hemophilia B?

A

Factor 9

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

What clotting factor is deficient in Hemophilia C?

A

Factor 11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  • Majority of these are inhibitors of clotting factors
  • They prevent the normal function of platelets and clotting factors
  • E.g. Factor 8 inhibitors and circulating anticoagulants
A

Autoantibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  • This anticoagulant can affect PT/PTT results
  • This is an autoantibody of unknown cause.
A

Lupus Anticoagulant

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

Lupus Anticoagulant

T or F: When in vitro, the anticoagulant will cause thrombosis and when in vivo, it will not clot the blood.

A

False

In vitro will not clot the blood, in vivo will cause thrombosis.

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

T or F: The majority of the clotting factors are produced in the kidney and are numbered 1 to 13.

A

False

They are produced in the liver.

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

What are the other clotting factors include?

A
  1. High molecular weight kininogen (HMWK)
  2. Prekallikrein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q
  • Decreased clotting of blood leading to bleeding
A

Hypocoagulation of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q
  • Uncontrolled clotting of blood leading to thrombosis (blockage in the vessel)
  • This is due to deficiencies of proteins that control the clotting factor functions (e.g. protein C and S)
  • May also be due to excessive platelets in the blood released by the bone marrow (e.g. Polycythemia vera)
A

Hypercoagulation of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q
  • Molecular interactions maintain equilibrium between procoagulant and fibrinolytic activities.
A

Balance Mechanism

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

What are the two (2) components of the balance mechanism for hemostasis?

A

Clotting Activation and Bleeding

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

What are the four (4) additional factors that support the hemostatic process?

A
  1. Endothelial Cell Function
  2. Plateleg Plug Formation
  3. Stagnation Effects
  4. Protective Mechanisms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Additional Factors that Support the Hemostatic Process

  • Blood flow changes affect endothelial cell behavior.
  • Injury to endothelium triggers hemostatic and thrombotic
    responses.
A

Endothelial Cell Function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Additional Factors that Support the Hemostatic Process

  • If vascular injury exceeds platelet capacity, hemorrhage
    symptoms arise
A

Platelet Plug Formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Additional Factors that Support the Hemostatic Process

  • Reduced blood flow due to arterial disease or mechanical
    impedance can lead to thrombus formation and
    hypercoagulable states.
A

Stagnation Effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Additional Factors that Support the Hemostatic Process

  • Intact endothelial cells are thromboresistant via receptor
    and proteoglycan interactions.
  • Coagulation proteins circulate as inactive zymogens,
    balanced by anticoagulant and fibrinolytic pathways.
  • Platelet procoagulant lipids are internalized within cells to
    maintain hemostatic balance.
A

Protective Mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the two (2) systems involved in maintaining hemostasis?

A

Major System and Minor System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Major or Minor System?

  • Vascular System
  • Platelets
  • Coagulation System
  • Fibrinolytic System
  • Serine protease inhibitors
A

Major System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Major or Minor System?

  • Kinin System
  • Complement System
A

Minor System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the three (3) general components of hemostasis?

A
  1. Extravascular
  2. Vascular
  3. Intravascular
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

General Components of Hemostasis

  • Mainly the tissue surrounding the damaged BVs (e.g. skeletal and smooth muscles)
  • These can contract to prevent further bleeding
  • Provide back pressure on the injured vessel through
    swelling and trapping of escaped blood.
  • Increased tissue pressure tends to collapse venules and
    capillaries.
A

Extravascular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

General Components of Hemostasis

T or F: Heavy bleeding occurs more frequently in areas with few skeletal muscles surrounding it (e.g. head)

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Extravascular Hemostatic Component

What are the (3) factors affecting hemostasis by surrounding tissues?

A
  1. Bulk or Amount of Surrounding Tissue
  2. Type of Tissue Surrounding the Injured Vessel
  3. Tone of the Surrounding Tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Factors Affecting Hemostasis by Surrounding Tissues

  • A wound in a fleshy area (e.g., thigh) will not bleed as
    profusely as an identical wound in an area with less tissue
    (e.g., scalp)
A

Bulk or Amount of Surrounding Tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Factors Affecting Hemostasis by Surrounding Tissues

  • Skeletal muscle is more absorbent and effective in
    arresting hemorrhage compared to loose connective
    tissue.
A

Type of Tissue Surrounding the Injured Vessel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Factors Affecting Hemostasis by Surrounding Tissues

  • Tissue elasticity affects the amount of bleeding.
  • Identical wounds in a 17-year-old with great tissue
    elasticity tend to bleed less than those in a 71-year-old with
    less tissue elasticity.
A

Tone of the Surrounding Tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

General Components of Hemostasis

  • Refers to the blood vessels
  • Diseases of the blood vessels may lead to bleeding despite having functional clotting factors
A

Vascular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the three (3) components of the vascular system?

A
  1. Arteries
  2. Veins
  3. Small Vessels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the importance of collagen?

A

Blood vessel resiliency and platelet activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

T or F: When a cut occurs, collagen is exposed which initiates platelet function.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is the contribution of chemicals released by blood vessels to clotting?

A

Promote or prevent blood clotting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the contribution of the surfaces of the blood vessels to clotting?

A

Provides sites for blood clotting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

General Components of Hemostasis

A genetic disorder that affects collagen formation

A

Ehlers-Danlos and Marfan Syndrome

44
Q

General Components of Hemostasis

T or F: Collagen contributes to the deactivation of platelets.

45
Q

General Components of Hemostasis

  • This is what’s contained plasma
A

Intravascular

46
Q

What are the three (3) components in the intravascular system needed for blood coagulation?

A
  1. Platelets
  2. Clotting Factors
  3. Calcium
47
Q

General Components of Hemostasis

What are the three (3) components of the intravascular component of hemostasis?

A
  1. Platelets
  2. Coagulation Proteins
  3. Fibrinolysis
48
Q

General Components of Hemostasis

The fibrinolytic system contains ____ which is able to dissolve the clot that was formed.

A

Fibrinolysin or Plasmin

49
Q

Fibrinolysis

The inactive form that circulates the body when it is not needed

A

Plasminogen

50
Q

Fibrinolysis

  • Responsible for activating or converting plasminogen
  • Can either be exogenous or endogenous
A

Plasminogen Activators

51
Q

Fibrinolysis

The active form that can digest the clot to allow for wound healing of damaged tissue

52
Q

Fibrinolysis

T or F: Excessive activity of plasmin can easily dissolve the clot, making it soft and harder to heal.

53
Q

Fibrinolysis

What are the two (2) manual methods for determining plasmin action?

A
  1. Whole blood clot lysis time
  2. Euglobulin lysis time
54
Q

What are the two (2) divisions of hemostasis?

A
  1. Primary
  2. Secondary
55
Q

Divisions of Hemostasis

The main objective is to form a platelet plug

56
Q

Primary Division of Hemostasis

T or F: Hemorrhaging does not only mean that blood needs to come out of the body, it can also occur internally.

57
Q

Primary Division of Hemostasis

It is only upon this certain circumstance that the components mentioned in the primary division of hemostasis will be activated.

A

Injury or damaged blood vessels

58
Q

Primary Division of Hemostasis

What are the five (5) components needed in order for platelets to clump together at a damaged site to form a plug?

A
  1. Blood Vessels
  2. Platelets
  3. Von Willebrand’s Factor
  4. Calcium
  5. Factor 1 (Fibrinogen)
59
Q

Primary Division of Hemostasis

  • Allows platelet adhesion to the blood vessel’s collagen
  • The disease associated with this have different types depending on the cause
A

Von Willebrand’s Factor

60
Q

Primary Division of Hemostasis

Deficiency of this leads to bleeding

A

Calcium (Hypocalcemia)

61
Q

Primary Division of Hemostasis

Allows platelet clumping or aggregation

A

Factor 1 (Fibrinogen)

62
Q

Primary Division of Hemostasis

A test that assesses/screens a possible defect in the primary division of hemostasis

A

Bleeding Time (BT)

63
Q

Primary Division of Hemostasis

Any abnormal result in BT points to a problem in what?

A

Platelet plug formation

64
Q

Primary Division in Hemostasis

What are the five (5) methods for Bleeding Time?

A
  1. Duke’s Method
  2. Ivy’s Method
  3. Modified Ivy’s Method
  4. Simplate Method
  5. Template Method (Modification of Ivy’s)
65
Q

The main objective is to stabilize the plug formed to form a firm clot

Now involves clotting factors.

66
Q

Secondary Division of Hemostasis

  • A test that assesses and screens a possible defect in the clotting factors
  • Not confirmatory for what specific clotting factor is impaired
  • Is requested in tandem with Bleeding Time
A

Clotting Time

67
Q

Secondary Division of Hemostasis

What are the two (2) methods for Clotting Time?

A
  1. Lee and White method
  2. Slide/drop method
68
Q

Secondary Division of Hemostasis

What is the reference value of PT upon the addition of specific reagents?

A

12 to 14 seconds

69
Q

Secondary Division of Hemostasis

What is the reference value of PTT/aPTT upon the addition of specific reagents?

A

20 to 45 seconds

70
Q

Secondary Division of Hemostasis

What are the three (3) chemical processes that occur with the clotting factors to form a clot?

A
  1. Extrinsic Pathway
  2. Intrinsic Pathway
  3. Common Pathway
71
Q

Secondary Division of Hemostasis

  • Involves Factor 7
  • Requires a specific reagent to activate this pathway
  • It uses PT to assess any defects (also applies to the common pathway)
A

Extrinsic Pathway

72
Q

Secondary Division of Hemostasis

  • Involves Factors 8, 9, 11, 12, HMWK, and Prekallikrein
  • Requires a specific reagent to activate this pathway
  • Uses PTT to assess any defects (also applies to the common pathway)
A

Intrinsic Pathway

73
Q

Intrinsic Pathway

This factor is the most common, especially for males.

74
Q

Secondary Division of Hemostasis

  • The activation of the either the extrinsic or intrinsic pathway to form a clot
  • Involves factors 1, 2, 5, 10, and 13 (cannot be assessed by either PT/PTT)
  • Utilizes both PT and PTT depending on what pathway is activated
A

Common Pathway

75
Q

How are platelets formed?

A

Megakaryopoiesis

76
Q
  • This is produced by the liver
  • When this hormone goes through the bone marrow, it activates stem cells to produce platelets
A

Thrombopoietin

77
Q

Megakaryopoiesis

These are needed for the successful maturation of platelet-producing cells.

A

Interleukins 3, 6, 7, and 11

78
Q

Phases/Stages of Development

  • 20 to 45 µm
  • Has an NC ratio of 4:1
  • The nucleus is oval to kidney-shaped, placed either centrally or eccentrically, and has red-purple fine chromatin granules
  • Has 1-2 nucleoli
  • The cytoplasm is basophilic, non-granular, and has pseudopodia
  • Has cytoplasmic tags (protrusions on the surface) due to immaturity
A

Megakaryoblast (MK 1)

79
Q

Phases/Stages of Development

  • 20 to 80µm
  • An NC ratio of 4:1 to 1:1
  • The nuclei (2) are oval and indented, placed either centrally or eccentrically, and have increased red-purple fine chromatin granules
  • Gas 0-1 nucleoli
  • The cytoplasm is basophilic, with fine azurophilic granules, and with abundant pseudopodia
  • Whenever the granules are forming, cytoplasmic channels (aka the demarcating membrane system) also start to get formed
A

Promegakaryocyte (MK 2)

80
Q

Phases/Stages of Development

  • 30 to 100µm
  • Has an NC ratio of 1:1 to 1:12
  • The nuclei (2 or 4) are lobulated, interconnected (fused), granulated, and with a central blue purple color
  • Has no nucleoli
  • The cytoplasm is pale blue with an abundance of pink
  • They are not really cells, these are merely fragments of the cytoplasm of one big cell
    -The minimum number of nuclei needed to release platelets is 4
  • Does not contain cytoplasmic tags anymore
A

Megakaryocyte (MK 3)

81
Q

Phases/Stages of Development

  • 30 to 100µm
  • Has an NC ratio of 1:1 to 1:12
  • The nuclei (4 or more; even numbers up to 32) are lobulated (2 or more lobes)
  • The cytoplasm is granular, with demarcation lines, pale blue with an abundance of pink, and contains numerous fine azurophilic granules
  • The platelets are ready to be deployed/fragmented out of the cytoplasm
A

Metamegakaryocyte

82
Q

Phases/Stages of Development

How many days does it to complete the stages of megakaryopoiesis?

A

5 to 7 days

83
Q

Phases/Stages of Development

Megakaryopoiesis produces how many metamegakaryocytes at a time?

84
Q

Phases/Stages of Development

T or F: The cytoplasm of a metamegakaryocyte divides, not the nucleus.

A

False

The cytoplasm does not divide but the nucleus does.

85
Q

Phases/Stages of Development

  • Division of the nucleus only but still with a complete set of 23 chromosomes each which causes the cytoplasm to expand
A

Endomitotic Division

86
Q

What are the two (2) release of platelets theories?

A
  1. Platelet Shedding Theory
  2. Fragmentation/Budding Theory
87
Q

Release of Platelets Theories

  • Megakaryocytes will squeeze a portion of their cytoplasm through blood vessels in the bone marrow via pseudopodia
  • Due to the blood flow, the cytoplasmic sheath will be cut with the platelets inside
  • The fragmented portion will be dragged along the circulation
  • Enzymes in our plasma will dissolve the sheath, releasing the platelets
A

Platelet Shedding Theory

88
Q

The Release of Platelets Theories

  • The platelets will fragment in the cytoplasm of the metamegakaryocyte
  • It will eventually enter the sinuses/blood vessels in the bone marrow before being dragged through the circulation
A

Fragmentation or Budding Theory

89
Q
  • 2 to 4µm
  • A blue cell with fine azurophilic granules—whatever we see in the cytoplasm of the metamegakaryocyte, it is the same for the platelet
  • Is anucleated without a golgi and rough ER
  • Approximately takes 1 week to produce
A

Thrombocytes

90
Q

____ are circulating while the ____ are sequestered or stored in the spleen.

A

70% are circulating while 30% are sequestered or stored

91
Q

In cases of splenomegaly, the (increased/decreased) size will attract more platelets causing a (decrease/increase) in plasma platelets.

A

Increased, decrease

92
Q

In cases of a splenectomy, all platelets will now be found in the circulation therefore (increasing/decreasing) in number.

A

Increasing

93
Q

What is the usual lifespan of thrombocytes?

A

5 to 7 or 7 to 10 day lifespan

94
Q

What is the reference values of thrombocytes?

A

50-350 (or 140-400)x 10^9/L or 150,000-350,000 cells per µm

95
Q

What are the three (3) zones in the ultra-structural zones?

A
  1. Peripheral Zones
  2. Sol-Gel Zones (Cytoskeleton)
  3. Organelle Zones
96
Q

What are the five (5) components under the peripheral zones?

A
  1. Glycocalyx
  2. Glycoprotein Receptors
  3. Platelet Membranes
  4. Open Canalicular System
  5. Sub-membranous Regions
97
Q

Platelets

This glycoprotein receptor is essential for platelet adhesion.

A

Glycoprotein 1A/IX/V (1A-9-5)

98
Q

Glycoprotein 1A/IX/V

Defect of the glycoprotein complex leading to poor adhesion

A

Bernard Solier Syndrome

99
Q

Platelets

This glycoprotein receptor is essential for platelet aggregation. (e.g. Glanzzman Thrombasthenia)

A

Glycoprotein 2B/3A

100
Q

Ultra-structural Zones

Channels that act as openings

A

Open Canalicular System (OCS)

101
Q

Ultra-structural Zones

Extension of the sol-gel zone

A

Sub-membranous Region

102
Q

What are the two (2) components of the sol-gel zones?

A
  1. Microtubules and microfilaments
  2. Actin Myosin/Thrombostenin
103
Q

Sol-gel Zones

  • Maintains the shape and appearance of the cell
  • It will be disrupted when activated
A

Microtubules and microfilaments

104
Q

Sol-gel Zones

  • Contractile protein that contracts upon activation to release the granuleslocated in the organelle zone
A

Actin Mysoin/Thrombostenin

105
Q

Hi, please study the platelet granules and overview of hemostasis.

A

Good job sa first lesson, see you next week. <3

Hematology 2 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions