Anticoagulants Flashcards
4 main steps in hemostasis
- vasoconstriction
- platelet aggregation (plug)
- coagulation (clot)
- thrombolysis
what allows for platelet aggregation
platelets cross-linked by fibrinogen binding to GPIIb/IIIa
platelet activation happens when bound to what
collagen
only molecule of coagulation cascade made by EC
vWF
clotting factors of coagulation cascade besides vWF made by what
liver hepatocytes
direct binding of platelet to collagen by what
GPVI
indirect binding of platelet to collagen
vWF: GPIIb/GPIIIa
cytokines inhibit antithrombotic factor and promote thrombotic factors
septic shock thrombosis pathogenesis
heparan sulfate
PGI2
NO
Adenosine
t-PA
thrombomodulin
anti-thrombotic factors produced from EC
vWF
PAI1 (Ang IV receptor)
tissue factor (factor III)
thrombotic factors produced from EC
thrombin receptor that activates protein C and turns thrombin into anti-coagulant
thrombomodulin
found in blood that will be used in platelet aggregation
fibrinogen
what happens for platelets to degranulate
they bind with GPIIb/GPIIIa and GPVI to vWF on subendothelium
how platelet is activated by TXA2 and 5-HT (serotonin)
TXA2 and 5-HT bind Gq receptor on platelet and cause increase in Ca2+
increased Ca2+ from TXA2 and 5-HT binding to Gq on platelet allows for what
activation of GPIIb/IIIa to bind to fibrinogen
how ADP activates platelet
binds P2Y12 (Gi) and decreases cAMP and activates GpIIb/IIIa
crosslinking by fibrinogen via GPIIb/IIIa
platelet aggregation
tissue factor (factor III) so powerful it does what when bound to platelet
directly activates GPIIb/GPIIIa
how thrombin activates platelet
thrombin binds PAR1 (Gq) and leads to degranulation
when platelets are activated what happens
degranulation and ready to bind fibrinogen (step 1 achieved)
lack of vWF (EC problem); mucosal bleeds (nose); most common bleeding disorder; AD
vWD
nose bleeds
epistaxis
stabilizes factor VIII and protects it from inactivation by Protein C
vWF
2 main functions of vWF
platelet aggregation and saving factor VIII
lack of vWF will affect what stages of coagulation
increased (PTT)
2nd most common bleeding disorder; x-linked recessive
Hemophilia A
males of Royal family were affected by this bleeding disorder
Hemophilia B
mutation in Factor V causes it to not be inactivated by protein C; propensity to form clots (thrombosis)
Factor V Leiden
GpIb deficiency (platelet problem)
Bernard-Soulier
Gp IIb/IIIa deficiency
Glanzmann thromboasthenia
made by Stellate cells in the liver
ADAMTS13
multimeric vWF used for adhesion is degraded by what
ADAMTS13
Ab against ADAMTS13, causes accumulation of vWF and thrombosis (TTP)
Ticlopidine
abnormal function of this makes collagen (can lead to cirrhosis of liver)
Stellate cells of liver
endothelial cell exocytotic bodies
Weibel-Palade body
cAMP associated exocytosis when V2 (Gq) is bound
Weibel-Palade body exocytosis
what is carried in the Weibel-Palade body
vWF
V2 receptor agonist (increases release of vWF from EC Weibel-Palade Body)
Desmopressin
what to administer in patient w/ DIC that has no platelets available and clotting factors being used in the disseminated clots
Desmopressin
no platelets available and clotting factors being used in the disseminated clots
consumption coagulopathy
defective platelet aggregation due to absent fibrinogen
Afibrinogenemia
what test to use to tell if vWF or GpIb is deficient
Ristocetin induced platelet aggregation (RIPA)