BL- COAG 2 Flashcards
Antithrombin: A serpin
serine protease inhibitor
inhibits coagulation
Does antithrombin only inhibit thrombin?
NO
2a and 10a also
A highly sulfated glycosaminoglycan
A commonly used anticoagulant
Acts as a cofactor for antithrombin
Heparin
Heparan sulfate, a related compound, produced by endothelial cells (masts and basos)
Another Vitamin K-dependent serine protease
Activated by thrombin
Inactivates Factor Va and Factor VIIIa
Protein S is a cofactor
Protein C
Factor V Leiden: A mutation of factor V that makes it resistant to ________ by protein C
inactivation
*“APC resistance.”
a small protein molecule that inactivates several enzymes of the coagulation system.
Antithrombin
Protein C inactivates
Factor Va and Factor VIIIa
performs these operations primarily by proteolytically inactivating proteins Factor Va and Factor VIIIa.
Protein C
Common risk factor for venous thromboembolism
Factor V Leiden
A mutation of factor V
*“APC resistance.”
A proteinase inhibitor
Constitutively expressed by endothelial cells
Inhibits extrinsic tenase by binding and inactivating the complex
Tissue Factor Pathway Inhibitor (TFPI)
Anticoagulation mechanisms
- Antithrombin
- Tissue Factor Pathway Inhibitor (TFPI)
- Factor V Leiden
- Protein C
- Heparin
genetically inherited disorder of blood clotting. ___________ is a variant of human factor V that causes an increase in blood clotting (hypercoagulability)
Factor V Leiden
a single-chain polypeptide which can reversibly inhibit Factor Xa (Xa).
Tissue Factor Pathway Inhibitor (TFPI)
a process that prevents blood clots from growing and becoming problematic.[1] This process has two types
Fibrinolysis- Key enzyme: Plasmin
Plasmin
Derived from plasminogen through cleavage by tissue plasminogen activator (t-PA) or urokinase (u-PA)
Plasminogen Activator Inhibitor-1 (PAI-1)
Binds to t-PA and u-PA and inactivates them
an important enzyme present in blood that degrades many blood plasma proteins, including fibrin clots.
Plasmin
serpin that functions as the principal inhibitor of tissue plasminogen activator (tPA) and urokinase (uPA), the activators of plasminogen and hence fibrinolysis (the physiological breakdown of blood clots).
Plasminogen Activator Inhibitor-1 (PAI-1)
important fibrin degreadation products
D Dimer
Inhibition of Fibrinolysis
Plasminogen Activator Inhibitor-1 (PAI-1)
a2- antiplasmin
thrombin- activatable fibrinolysis inhibitor
a serine protease inhibitor (serpin) responsible for inactivating plasmin, an important enzyme that participates in fibrinolysis and degradation of various other proteins.
Alpha 2-antiplasmin
An exopeptidase involved in Inhibition of Fibrinolysis
Thrombin-Activatable Fibrinolysis Inhibitor (TAFI)
a fibrin degradation product (or FDP), a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis.
D Dimer
α2-Antiplasmin
Another serpin
Binds to plasmin and inactivates it
____ is used in some cases of diseases that feature blood clots, such as pulmonary embolism, myocardial infarction, and stroke, in a medical treatment called thrombolysis
Therapeutic tPA
In resting state, _______tends to prevent clotting
Endothelium
Produces heparan sulfate
Endothelium Resting state
Endothelium Exposure of tissue factor
With vessel damage, promotes clot formation
Expresses thrombomodulin → protein C activation
Endothelium Resting state
With vessel damage, _______promotes clot formation
Endothelium
Release of von Willebrand factor from Weibel-Palade bodies of the endothelial cells
With vessel damage, endothilum promotes clot formation
Expresses TFPI
Endothelium Resting state
von Willebrand factor
a blood glycoprotein involved in hemostasis
primary function is binding to other proteins, in particular factor VIII, and it is important in platelet adhesion to wound sites
Exposure of subendothelium, leading to platelet adhesion and activation
With vessel damage, endothilum promotes clot formation
Binds to subendothelium via collagen, von Willebrand factor, and other proteins
Role of the platelet
Forms a platelet plug at the site of injury
Role of the platelet
Synthesizes t-PA and u-PA
Endothelium Resting state
Release of substances that cause vasoconstriction
With vessel damage, endothilum promotes clot formation
With activation, exposes anionic phospholipids that act as a surface for coagulation to take place
Role of the platelet
Synthesizes PGI2 (prostacyclin) and nitric oxide → vasodilitation
Endothelium Resting state
Releases multiple substrates for coagulation
Role of the platelet
Metabolizes ADP (platelet agonist) to AMP + adenosine (platelet inhibitor)
Endothelium Resting state
a blood glycoprotein involved in hemostasis
primary function is binding to other proteins, in particular factor VIII, and it is important in platelet adhesion to wound sites
Von Willebrand factor’s
is Von Willebrand factor’s an enzyme?
No- It is NOT an enzyme and, thus, has no catalytic activity.
dRVVT
good if prolonged aPTT activates factor 10 if SLE (antiphoslipid) this test wont change
APS
Antiphospholipid SLE
must ave positive AB panal 6 weeks apart in setting of miscarriage or thrombosis
Labs for DIC
Fibrinogen D-Dimer CBC PT aPTT
How do you ALWAYS treat DIC
Treat the underlying disorder
Prolonged PT Greatly prolonged PTT Prolonged thrombin time Low platelet count Low fibrinogen level Increased fibrin split products Increased D-dimer
Labs for DIC
