Hematology Exam 3 Flashcards
Factor I
Fibrinogen
activates GPIIb/IIIa complex
Factor II
Prothrombin
Factor III/TF
Tissue Factor, Thromboplastin
attracts platelets activates EXTRINSIC patways
Factor IV
Ionic Calcium
Factor V
Labile factor
Factor VII
Stable factor
Factor VIII
Antihemophilc factor
Factor IX
Christmas factor
Factor X
Stuart-Prower factor
activation starts COMMON pathway
Factor XI/PTA
Plasma thromboplastin atecedent
Factor XII
Hageman factor
Factor XIII/FSF
Fibrin-stabilizing factor
VWF
Von Willebrand factor
Factor VII carrier
Platelet adhesion to vessel wall
absence causes pseudohaemophilia
Pre-K
Prekallikrein/Fletcher factor
HMWK
High molecular weigh kininogen/ Fitzgerald factor
PF3
Platelet factor 3/Phosphoplids, phosphatidylserine
stimulates coagulation process
activates INTRINSIC pathway
activates EXTRINSIC pathway
PF4
Platelet factor 4
stimulated by PF3
starts the coagulation cascade
t-Pa
Tissue Plasma activator
converts plasminogen to plasmin
PAI-1/PAI-2
Plasminogen activator inhibitor- 1 or 2
Inactivate t-Pa (stops plasminogen -> plasmin)
Define intima
inner vessel wall
Define media
middles vessel wall
Define adventitia
outer vessel wall
Define thrombocytopenic purpura
bruising associated with a reduced number of circulating platelets
Define fibrin
fibrillar protein produced by the action of thrombin on fibrinogen in the clotting process. Fibrin is responsible for the semisolid character of a blood clot.
Define Disseminated Intravascular Coagulation (DIC)
occurs after traumatic event. Affected person has used up all of their clotting factors and begins to hemorrhage. Lethal within an hour. True STAT situation.
What is Coumandin (Warfarin)
anticoagulant medication which inhibits the uptake of vitamin K uptake in liver cells.
Define serine protease inhibitor
inactivates fibrynolytic enzymes when no longer needed, stops fibrinolysis when it is complete
Define Kinin System
important in inflammation, vascular permeability, and chemotaxis
What is the complement system?
cell membrane lysis of antibody-coated target cell
Define Plasminogen activator inhibitor
neutralize fibrinolytic enzymes; too much leads to a risk of thrombosis
Describe adhesion
the attachment of platelets to the subendothelial collagen. Reversible; seals endothelial gaps, some secretion of growth factors. In arterioles VWF (von Willebrand factor) is necessary for adhesion.
Describe Aggregation
Platelets adhere to each other. Irreversible; platelet plug forms, platelet contents are secreted, requires fibrinogen.
Describe Secreation
platelets discharge to contents of their granules. Irreversible; occurs during aggregation, platelets contents are secreted, essential to coagulation.
Define Primary Hemostasis
the role of blood vessels and platelets in the initial formation of a primary hemostatic plug in response to vascular injury. Limits bleeding immediately. Initiates the clotting cascade and maintains vascular integrity
How is primary hemostasis activated?
“Injuries to the blood vessel
Exposure of collagen and TF (tissue factor/factor III)”
Define Mucocutaneous hemmorrhage
bleeding on surface of the skin
Define Eccymoses
purpue, bruising
Define epistaxis
nosebleeds
Define petechia
broken cappillaries
What factors are needed for platelat adhesion?
VWF, collagen, GPIB
Define dense bodies
granules containing ADP in platelets, occurs after platelet is activated
Platelets secrete granules containing ADP for
energy, attraction of other platelets
What is required to make the primary hemostatic plug?
ATP (for energy), Ca2+, GPIIB and GPIIIa, Fibrinogen (factorI)- this activates a GPIIb/GPIIIa complex
What starts the coagulation cascade?
The release of platelet factor 4 (PF4)
Define secondary hemostasis
second phase of coagulation involving the activation of plasma coagulation proteins to produce a fibrin clot. This is the coagulation cascade. The polymerization of multiple fibrin strands into a single clot.
Which pathway does platelet factor 3 (PF3) trigger?
Both the INTRINSIC and EXTRINSIC pathways
Symtpoms of Secondary Hemostasis
Factor deficiencies, coumadin toxicity, heparin therapy, DIC, haemophilia)
What is the intrinsic pathway?
sequence of serine protease reactions leading to fibrin formation, beginning with the in vitro activation of factor XII, followed by the sequencial activation of factors XI and IX, and resulting in the activation of factor X, which initiates the common pathway of coagulation. Triggered by internal injuries such as bruising.
What is the extrinsic pathway?
primary in vivo coagulation pathway. Exposure of tissue factor activates factor VII. Factor VIIa activates factor IX and X, which triggers the common pathway of coagulation and the formation of fibrin. Triggered by injuries from the outside (surgery, trauma, ect)
What is the common pathway?
the steps in the coagulation cascade from the activation of factor X through the conversion of fibrinogen to fibrin. The common pathway begins at the junction of the intrinsic and extrinsic pathways and involves factor X, V, II (prothrombin), and fibrinogen in order of reaction.
Heparin limits which pathway?
INTRINSIC
Coumadin limits which pathway?
EXTRINSIC
The intrinsic pathway is activated by…
“Collagen
PF3”
The extrinsic pathway is activated by…
“TF (tissue factor/factor III)
calcium
PF3”
How long does a fibrin clot typically last?
3-5 days
Symtpoms of fibrinolysis disorders
“Hemorrhage
Oozing
DIC”
In fibrinolysis, what converts plasminogen to plasmin?
tissue plasma activator (t-Pa) and urokinase
In fibrinolysis, what inihbits the conversion of plasminogen to plasma?
plasminogen activator inhibitor 1 and 2 (PAI-1/2)
X and Y products
are larger FDPs
D and E products
are smaller FDPs, fibrin splits
What stops fibrinolysis when the cot is dissolved?
Thrombin-activatable fibrinolysis inhibitor
Define thrombopoiesis
the formation of platelets
How many nuclei does a promegakaryocyte have?
two - four
How many nuclei does a magakaryocyte have?
eight to thirty two
Where are megakaryocytes stored?
lungs and bone marrow
How many platelets does one megakaryocyte produce?
2,000-7,000
What is the normal range for platelets?
150,000-350,000
Define splenomegaly
enlargement of the spleen
Define hypersplenism
increased hemolytic activity of the spleen caused by splenomegaly, resulting in deficiency of peripheral blood cells and compensatory hypercellularity of the bone marrow
Platelets provide a negatively charged phospholipid surface for the activation of which factors?
factor X (stuart-prower) and factor II (prothrombin)
Plateles provide surface membrane glycoproteins too…
attract other platelets
What platelets secretions can be used as activation markers?
Beta-thromboglobulin, PF4, thrombosondin, and PDGF
Where are most platelets found? Name 1 exception
“The liver
VWF portion of factor VII is produced in epithelial cells and platelets”
Define cofactor
A substance whose prescence is essential for the activity of an enzyme
In coagulation, one of the main cofactors is…
calcium
Define protrombin time (PT)
measures the extrinsic pathway. Thromboplastin and calcium are added to plasma and the clotting time is recorded. Widely used to measure Coumadin therapy.
more sensitive to the loss of factor VII than to factor II
inhibited by Coumadin which inhibits vitamin K uptake in liver cells
Define partial prothrombin time (PTT)
“measures the intrinsic pathway. Calcium chloride, phospholipid, and activator are added to patient plasma. The interval from the addition of reagent to clot formation is recorded. The test is used to monitor unfractionated heparin therapy, to screen for intrinsic pathway deficiencies, and to screen for lupus anticoagulation.
most sensitive to intrinsic pathway deficiencies occuring in the cascade prior to factor II
inhibited by heparin
when T is prolonged by Coumadin, the PTT is also slightly prolonged.
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