7-ADD PRIMARY HOMEOSTASIS Flashcards
1
Q
What is the first step in forming a platelet plug
A
Platelet adhesion to exposed subendothelial connective tissue
2
Q
What protein mediates the initial attachment of platelets to subendothelial collagen
A
von Willebrand factor (VWF)
3
Q
Where is vWF synthesized
A
Endothelial cells and megakaryocytes
4
Q
What binds to exposed collagen
A
VWF
5
Q
What complex does VWF-Collagen bind
A
Glycoprotein Ib/IX/V complex on platelet surface
6
Q
What enhances platelet adhesion
A
GP VI (collagen-binding receptor)
7
Q
What interaction induces intracellular signals leading to platelet activation
A
GP VI interaction with collagen
8
Q
What results from GP VI interaction with collagen
A
Shape change+granular release+integrin activation
9
Q
What protein promotes the stable binding of platelets to subendothelial collagen
A
Integrin α2β1 (GP Ia/IIa)
10
Q
What does Platelet Activation require
A
Adhesion+Activation+Aggregation
11
Q
What do agonists activate
A
Platelets
12
Q
Name some platelet agonists
A
Thrombin+ADP+TXA2
13
Q
What results from Platelet Activation
A
Shape Change+Secretion of Granules+Arachidonic Acid Pathway+Phospholipid Metabolism+GP IIb/IIIa Activation
14
Q
What is the initial shape of platelets
A
Discoid
15
Q
What happens to the shape of platelets after being activated
A
Become spherical
16
Q
What does shape change expose on the platelet surface
A
Phosphatidylserine
17
Q
What does Phosphatidylserine enhance
A
Assembly of coagulation protein complexes
18
Q
What molecules polymerize forming the platelet’s cytoskeleton
A
Actin and myosin
19
Q
What is exposed during secretion of granules
A
P-selectin (CD62P)
20
Q
What is required for Platelet Aggregation
A
Glycoprotein IIb/IIIa (integrin αIIbβ3)
21
Q
What promotes binding of platelets to one another
A
Fibrinogen binding to activated GP IIb/IIIa
22
Q
What is bound by Activated GP IIb/IIIa on Platelets
A
Fibrinogen
23
Q
What does Binding of Fibrinogen promote
A
Platelet-Platelet interaction
24
Q
What results from Binding of Fibrinogen to adjacent platelets
A
Formation of Platelet Aggregates
25
What strengthens and stabilizes the platelet plug
Fibrin
26
What results from the release of platelet agonists
Recruits additional platelets+amplifies process
27
What happens in irreversible platelet activation
Cell injury with platelet lysis
28
What results from cell injury with platelet lysis
Uncontrolled activation
29
What results from uncontrolled activation
Thrombosis
30
What prevents uncontrolled activation in hemostasis
Balance of procoagulant and anticoagulant forces
31
Which pathway is activated by large injuries that expose Tissue Factor (TF)
Secondary Hemostasis
32
What is Secondary Hemostasis the interaction of
Coagulation factors
33
What does Secondary Hemostasis result in
Formation of fibrin and a stabilized platelet-fibrin plug
34
What is the Cellular component in Secondary Hemostasis
Tissue Factor-Bearing Cell
35
What is the first step in the Cell-Based Model of Coagulation
Initiation
36
What cells express TF in-vivo
Cells surrounding blood vessels
37
What plasma factor does TF bind
Factor VIIa
38
What complex forms the extrinsic tenase complex
TF-VIIa
39
What converts Factor X to Factor Xa on the cell surface
TF-VIIa
40
What combines with Factor Xa to form the prothrombinase complex
Factor Va
41
What does Prothrombinase complex activate
Prothrombin to Thrombin
42
What cell does Initiation take place on
Tissue Factor-Bearing Cell
43
What is the second step in the Cell-Based Model of Coagulation
Amplification
44
What is the cell involved in amplification
Platelet
45
What requires small amount of thrombin generated in Initiation
Platelet Activation
46
What is required for Platelet Activation
Adhesion and agonists
47
What receptors do Thrombin
TXA2
48
What happens on Activated Platelets
Release of coagulation factors
49
What is the third step in the Cell-Based Model of Coagulation
Propagation
50
What is the cell involved in propagation
Platelet
51
What coagulation factors does Propagation require
Factors IXa
52
What is required for the Assembly of Factors IXa
VIIIa
53
What does Assembly of Factors IXa
VIIIa
54
What is generated in Thrombin Burst
Fibrin and stabilized platelet-fibrin plug
55
What happens in irreversible platelet activation
Cell injury with platelet lysis
56
What results from cell injury with platelet lysis
Uncontrolled activation
57
What results from uncontrolled activation
Thrombosis
58
What prevents uncontrolled activation in hemostasis
Balance of procoagulant and anticoagulant forces
59
Which pathway is activated by large injuries that expose Tissue Factor (TF)
Secondary Hemostasis
60
What is Secondary Hemostasis the interaction of
Coagulation factors
61
What does Secondary Hemostasis result in
Formation of fibrin and a stabilized platelet-fibrin plug
62
What is the Cellular component in Secondary Hemostasis
Tissue Factor-Bearing Cell
63
What is the first step in the Cell-Based Model of Coagulation
Initiation
64
What cells express TF in-vivo
Cells surrounding blood vessels
65
What plasma factor does TF bind
Factor VIIa
66
What complex forms the extrinsic tenase complex
TF-VIIa
67
What converts Factor X to Factor Xa on the cell surface
TF-VIIa
68
What combines with Factor Xa to form the prothrombinase complex
Factor Va
69
What does Prothrombinase complex activate
Prothrombin to Thrombin
70
What cell does Initiation take place on
Tissue Factor-Bearing Cell
71
What is the second step in the Cell-Based Model of Coagulation
Amplification
72
What is the cell involved in amplification
Platelet
73
What requires small amount of thrombin generated in Initiation
Platelet Activation
74
What is required for Platelet Activation
Adhesion and agonists
75
What receptors do Thrombin
TXA2
76
What happens on Activated Platelets
Release of coagulation factors
77
What is the third step in the Cell-Based Model of Coagulation
Propagation
78
What is the cell involved in propagation
Platelet
79
What coagulation factors does Propagation require
Factors IXa
80
What is required for the Assembly of Factors IXa
VIIIa
81
What does Assembly of Factors IXa
VIIIa
82
What is generated in Thrombin Burst
Fibrin and stabilized platelet-fibrin plug
83
What are the contact factors
Prekallikrein
84
What must happen to Factor XII before it can be activated
Absorb to a negatively charged surface
85
What are examples of negatively charged substances that Factor XII may absorb to
Glass
86
What is the role of Factor XIIa
Activates Prekallikrein to Kallikrein
87
What is the role of Kallikrein
Activates Factor XII
88
What is the role of Factor XIa
Activates Factor IX
89
What is the final product of the contact pathway
Factor IXa
90
What is Fibrinolysis
Enzymatic breakdown of fibrin in blood clots
91
What is the major enzyme of the Fibrinolytic system
Plasmin
92
What is the inactive precursor of Plasmin
Plasminogen
93
What converts Plasminogen to Plasmin
Tissue Plasminogen Activator (tPA)
94
What are other Plasminogen Activators
Urokinase-like Plasminogen Activator (uPA)
95
What is the function of Plasmin
Digests fibrin+degrades fibrinogen
96
What are the products of Plasmin's digestion of fibrin and fibrinogen
Fibrin Degradation Products (FDPs)
97
What are Fibrin Degradation Products (FDPs)
Fragments that result from clot breakdown
98
What is the function of D-Dimers
Measure amount of cross-linked fibrin degradation; marker for thrombosis
99
What prevents thrombin from uncontrolled clot formation
Regulated by: Antithrombin
100
Where is antithrombin synthesized
Liver
101
What does Antithrombin inhibit
Serine proteases (Factors IIa
102
What enhances antithrombin activity
Heparin
103
Where are Proteins C and S synthesized
Liver
104
What vitamin is required for Proteins C and S synthesis
Vitamin K
105
What does Protein C require to function
Protein S (cofactor) and Thrombomodulin
106
What does Protein C inactivate
Factors Va and VIIIa
107
What is Tissue Factor Pathway Inhibitor (TFPI)
Binds to Factor Xa+inhibits TF-VIIa complex
108
What does Factor V Leiden mutation cause
Resistance to Protein C
109
What does Prothrombin G20210A mutation cause
Increased prothrombin levels and thrombin generation
110
What is elevated in Hyperhomocysteinemia
Homocysteine levels
111
What does Hyperhomocysteinemia cause
Endothelial damage+increased risk of thrombosis
112
What are the acquired Thrombotic Disorders
Antiphospholipid syndrome+Heparin-induced Thrombocytopenia
113
What are the causes of Vascular disorders
Inherited or acquired defects in blood vessels
114
What is the role of vascular disorders in Hemostasis
Excessive Bleeding
115
What is Hereditary Hemorrhagic Telangiectasia also known as
Osler-Weber-Rendu disease
116
What causes Hereditary Hemorrhagic Telangiectasia
Thin vessel walls+telangiectases on skin/mucous membranes
117
What does Hereditary Hemorrhagic Telangiectasia result in
Epistaxis+GI bleeding+iron deficiency anemia
118
What is Easy Bruisability
Frequent or excessive bruising from minor trauma
119
What causes Easy Bruisability
Vessel wall defect
120
What are the symptoms of Senile Purpura
Easy bruising in elderly+sun-damaged skin+atrophy of subcutaneous tissues
121
What is the cause of Senile Purpura
Loss of supporting connective tissue around vessels
122
What are the symptoms of Allergic Purpura
Purpuric rash+abdominal pain+arthralgia+renal disease
123
What causes Allergic Purpura
Immunoglobulin A (IgA) deposition in small vessels
124
What is Ehlers-Danlos Syndrome
Defect in collagen synthesis or structure
125
What does Ehlers-Danlos Syndrome result in
Joint hypermobility+skin hyperextensibility+tissue fragility
126
What is Marfan Syndrome
Genetic disorder affecting connective tissue
127
What does Marfan Syndrome affect
Skeleton+heart+blood vessels+eyes
128
What causes Marfan Syndrome
Fibrillin-1 gene mutation
129
What vascular complications are associated with Marfan Syndrome
Aortic dissection+aortic aneurysm
130
What are the symptoms of Scurvy
Bleeding gums+bruising+poor wound healing
131
What causes Scurvy
Vitamin C deficiency
132
What is required for collagen synthesis
Vitamin C
133
What are the symptoms of Cushing Syndrome
Easy bruising+skin thinning+weight gain+muscle weakness
134
What causes Cushing Syndrome
Prolonged exposure to high cortisol levels
