hema cram Flashcards
(153 cards)
1
Q
What is the physiologic response to vascular injury?
A
Limit blood loss
2
Q
What are the characteristics of hemostasis?
A
Rapid, localized, well-regulated
3
Q
Who published a sequence of proteolytic reactions for coagulation?
A
MacFarland
4
Q
What begins the coagulation cascade?
A
Factor XII activation
5
Q
What substance does Thrombin proteolyze to form a clot?
A
Fibrinogen
6
Q
What did patients with Factor XII Deficiency show?
A
Did not bleed
7
Q
What is a key feature of the cell-based model of hemostasis?
A
Cellular elements express TF
8
Q
Which cells provide a phospholipid surface for coagulation?
A
Endothelium, Platelets
9
Q
What does Thrombin convert Fibrinogen into?
A
Fibrin Clot
10
Q
What are the two groups of zymogens in the Coagulation System?
A
Phospholipid-Bound, Surface-Bound
11
Q
What is the role of Vitamin K in coagulation proteins?
A
Essential for γ-carboxylation
12
Q
What does the γ-carboxylation reaction allow coagulation proteins to do?
A
Bind to phospholipid and cell membranes
13
Q
What is necessary for proteins FX, FIX, FVII, and FII to function normally?
A
Carboxylation reaction
14
Q
What does activated Protein C do?
A
Inactivates FVa and FVIIIa
15
Q
What role does Protein S play?
A
Natural anticoagulant
16
Q
What is K-dependent and acts as cofactor for APC?
A
Surface-Bound
17
Q
What are the proenzymes of the Plasma Kallikrein/Kinin System?
A
FXII, Prekallikrein, FXI
18
Q
What are the protein zymogens of the CONTACT SYSTEM?
A
FXII autoactivation
19
Q
What common laboratory test uses FXII autoactivation?
A
Activated Partial Thromboplastin Time (APTT)
20
Q
What are the types of Urokinase Plasminogen Activator?
A
ScuPA, TcuPA
21
Q
Where are these plasminogen activators found?
A
Endothelium, Neutrophils, Monocytes
22
Q
What do tPA, ScuPA, and TcuPA do?
A
Convert Plasminogen to Plasmin
23
Q
How is tPA produced?
A
Constitutively
24
Q
What increases ScuPA levels?
A
Inflammatory states
25
What is the major inhibitor of tPA and TcuPA?
Plasminogen Activator Inhibitor-1 (PAI-1)
26
What can TAFI do to control Plasmin?
Remove lysine residues from Fibrin
27
What is the active Plasmin molecule?
A potent protease
28
What does Plasmin do to soluble Fibrinogen?
Produces Fibrinogen Degradation Products
29
What does Plasmin cleave Fibrinogen into?
An X Fragment
30
What complex does TFPI form?
FVIIa, TF, FXa
31
Where is TFPI produced?
Microvascular endothelium
32
What condition is associated with murine TFPI knockout?
Embryonically lethal
33
Where is AβPP present?
Platelets and brain
34
Which factors does AβPP regulate?
XIa, IXa, Xa, VIIa/TF
35
What does AβPP not inhibit?
Thrombin
36
What enzyme produces Prostacyclins (PGI2)?
Cyclooxygenase-2
37
What is the function of PGI2?
Vasodilator, inhibits platelet aggregation
38
What hormone is involved in controlling hemostasis?
Vasoactive hormones
39
What are believed to be cerebral anticoagulants?
Prostacyclins, Nitric Oxide, Thrombospondin-5
40
How do Prostacyclins mediate their actions?
IP Receptors and PPARs
41
What enzyme do endothelial cells express?
eNOS (NOS3)
42
What is a significant function of Nitric Oxide?
Potent vasodilator
43
What does NO inhibit?
Platelet adhesion and aggregation
44
What does NO activate?
Guanylate Cyclase and cGMP
45
What do activated platelets produce under shear flow?
NO
46
What is Thrombospondin-5 also known as?
COMP
47
What type of protein is COMP?
Extracellular protein
48
What tissues release COMP?
Cartilage and muscle
49
Common presentations of Secondary Hemostasis defects?
Ecchymoses, soft tissue, joint bleeds
50
Types of bleeding tendencies?
Congenital or acquired
51
What is necessary before laboratory testing for bleeding?
Personal and family history
52
When are congenital bleeding disorders usually diagnosed?
Early childhood
53
When might mild bleeding disorders be revealed?
Later in life with hemostatic challenge
54
What are Routine Coagulation Screening Tests used for?
Identify hemostatic defects
55
Is it clinically useful to perform coagulation tests on nonbleeding patients?
Not clinically useful
56
What tests are considered screening coagulation tests?
PT, APTT, Fibrinogen, Thrombin Time, D-Dimers
57
What is the collection ratio for whole blood in Sodium Citrate?
9:1 Blood:Citrate
58
How should blood specimens be mixed after collection?
Gently invert 3 to 5 times
59
What is the transport requirement for the specimen?
Room temperature, within 4 hours
60
What should be done if testing cannot be performed within 4 hours?
Centrifuge and freeze
61
Why should separated plasma be platelet free before freezing?
To prevent false low anti-FXa
62
What is the threshold for platelet count in separated plasma before freezing?
<10 K
63
What does platelet factor 4 bind to?
Heparin
64
What is the Fibrin Stabilizing Factor?
XIII
65
Cellular Component consists mostly of what?
PLATELETS and ENDOTHELIAL CELLS
66
What does the Large Group of Plasma Proteins participate in?
clot formation
67
What is vascular integrity BREACHED?
vascular injury
68
Where is it found?
most tissues and cells
69
What is the cause of the formation of complexes with FVII?
hemostatic reactions
70
What results in the formation of complexes with FVII that produce the initiation of hemostatic reactions?
Upregulation of TF
71
What is the cofactor for FIXa when it is activated?
FVIIIa
72
What is the most severe clinically recognized bleeding disorder?
Hemophilia A. FV
73
What is a protein with homology to FVIII?
330-kDa
74
What is the main substrate of FII?
Thrombin Fibrinogen
75
What is the principal adhesive molecule for platelet aggregation?
330-kDa
76
What proteolyzes Fibrinogen?
Thrombin
77
What is formed when Fibrinogen is proteolyzed by Thrombin?
a FIBRIN MONOMER
78
What type of FIBRIN CLOT do monomers associate end to end and side to side to form?
polymerized FIBRIN CLOT
79
What are the most prominent bleeding disorders that occur in patients who survive gestation and birth?
Deficiencies in coagulation Factors VIII and IX
80
What type of patients have congenital deficiencies of coagulation Factor VII, X, V, and II?
rare
81
Rare patients who have what type of deficiencies of coagulation Factor VII, X, V, and II usually do not have severe bleeding states?
congenital deficiencies
82
What is the order structure of the Prothrombinase Complex?
FII (Prothrombin)
83
What are the components of the Prothrombinase Complex?
phospholipid membranes or cell membranes
84
What is the Endothelial Protein C Receptor?
EPCR
85
What does the complex formed by APC+EPCR need to do to allow binding of APC with Protein S to inactivate FVa and
DISSOCIATE
86
How does APC bind to cell surfaces in a way that orients itself to inactivate?
FVa and FVIIIa
87
What does the enzyme use to localize its activity to perform its inhibitory function?
receptor
88
What is in equilibrium between the FREE FORM (40%) and a BOUND FORM (60%)?
Plasma Protein S
89
How many Receptors on Endothelial Cells bind APC to?
3
90
What is the PAR?
Protease-Activated Receptor
91
What may contribute to the anticoagulant function of Activated Protein C by liberating tPA?
Activation of PAR1
92
What is the inhibitor effect on FIIa Heparin Cofactor II?
4000-fold
93
What is Factor Xa dependent?
Vitamin K3
94
What is the causative factor for Types I and II Hereditary Angioedema?
The absence of C1 Inhibitor
95
What is the most potent inhibitor of the FVIIa-Tissue Factor Vomplex?
Kunitz-Type Serine Protease Inhibitor
96
Who was the downloader of lOMoARcPSD?
Princess Therese Timbal
97
What does COMP inhibit?
Thrombin
98
What are EXPOSED at the site of endothelial cell injury?
Subendothelial Collagen and Von Willebrand Factor
99
What does the platelet undergo from DISCOID to SPHERICAL?
SHAPE CHANGE
100
GPIb/IX/V Receptors are binding to what?
vWF
101
What is followed by platelet Adhesion?
SECRETION
102
What is the name of the path that releases the contents of Alpha and Dense Granules from Platelets?
the Cyclooxygenase-1 (COX-1) Pathway
103
What parts of Platelets are released during Secretion?
Alpha and Dense Granules
104
What causes ACTIVATION TXA2?
vasoconstriction
105
ACTIVATION TXA2 causes vasoconstriction and ACTIVATES PLATELETS via what?
TXA receptor
106
What leads to exposure of Phosphatidylserine?
Activation of Platelets
107
What does Phosphatidylserine begin to produce?
Thrombin
108
What can be divided into 2 different phases?
secondary Hemostasis
109
TF PATHWAY is the initiator of what?
coagulation 2.
110
What is the name of TF PATHWAY?
EXTRINSIC PATHWAY
111
INTRINSIC PATHWAY amplifies and propagates what?
thrombin generation
112
What does the TF Pathway begin with on the cell surface?
ENDOTHELIAL INJURY and EXPRESSION OF TF
113
What is the name of the complex that activates FX to FXa?
Extrinsic Tenase
114
Extrinsic Tenase activates FX to FXa on the cell surface in the presence of what?
Ca++
115
What does ASE COMPLEX form?
Thrombin
116
What is the cell surface of the FXa?
PL
117
What converts Prothrombin to Thrombin?
PROTHROMBINASE COMPLEX
118
What is the cell surface of the Intrinsic Pathway?
Ca++
119
What is the cell surface of FIXa?
PL
120
What forms the INTRINSIC TENASE?
FIXa
121
What is the primary pathway of THROMBIN FORMATION?
Intrinsic Pathway
122
What is the Intrinsic Pathway?
AMPLIFIER AND PROPAGATOR of Thrombin
123
What is the INITIATOR?
TF Pathway
124
What would patients with Hemophilia A and B have if they were independent pathways producing Thrombin?
bleeding tendencies
125
What are the test tubes that assess Thrombin?
Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT)
126
What is the main enzyme in the coagulation system?
Thrombin
127
What does Thrombin convert Fibrinogen to?
Fibrin Monomers
128
What does it activate to cross-link fibrin monomers to stabilize the clot?
FXIII to FXIIIa
129
What are released from platelet membranes?
Phospholipids
130
What do Phospholipids release from platelet membranes bind to?
Lupus Anticoagulant
131
How long should the specimen be held at room temperature?
4 hours
132
What is often encountered in office clinics that send out their specimens to remote reference laboratories for coagulation testing?
Improper sample handling
133
What part of coagulation testing is crucial for accurate diagnosis and management?
preanalytic
134
What does PT contain?
tissue Thromboplastin and CaCl2
135
What are the Coagulation Factors in the Intrinsic Pathway and what other path?
Common Pathway
136
What does APTT generally assess in the Intrinsic Pathway and Common Pathway?
Coagulation Factors
137
What type of contact factor is activated in APTT?
PLs
138
What is the activation of in APTT?
Contact Factors
139
How many different quantities of PL are available in the APTT reagents?
three
140
What are the three APTT reagents with different sensitivities for various needs?
a.
141
What does APTT-FS have the highest amount of?
PL
142
What is APTT-FS?
-Factor Sensitive
143
What is the smallest amount of PL?
weak LA
144
What does APTT-FSL detect?
decreased amounts of coagulation factors and lupus anticoagulant
145
What is the term for PL?
c. APTT-FSL
146
What is a common clinical finding?
prolonged APTT
147
What should further investigation be dictated by if the presenting symptom is the presenting symptom?
a personal and family history of bleeding
148
What is prolonged in a bleeding patient?
APTT
149
What should be considered and investigated by measuring FVIII first?
a CONGENITAL BLEEDING DISORDER of INTRINSIC PATHWAY
150
What is the name of the DISORDER of INTRINSIC PATHWAY?
FIX
151
Why is Thrombin time not a commonly ordered test?
limited utility
152
What is added to the patient's plasma and the clotting time recorded?
Bovine Thrombin
153
How long should the upper limit of the normal range be adjusted to make TT more sensitive to detect DYSFIBRINOGENEMIA?
25 sec
