18/19 - Hemostasis and Thrombosis Review Flashcards
components for platelet activation
glycoprtn 1b binds to vWF
other glycoprtns bind to collagen to activate platelets
activated platelets secrete
ADP
TXA2
5-Ht
these bind to platelets and activate GP IIb/IIIa
activated GP IIb/IIIa binds…
to fibrinogen
______ cleaves fibrinogen into fibrin
thrombin
thrombin further activates platelets b binding to and activating the _________
protease activated receptor PAR
how does thrombomodulin work in the anticoagulation system?
thrombomodulin pairs with thrombin on a receptor on endothelial cells that activates prtn C to APC which activates prtn S whcih inhibits VIIIa and Va to stop the formation of thrombin
what does antithrombin do?
inactivates thrombin and factor Xa
what is the role of heparin sulfate?
binds antithrombin and significantly increases rate of thrombin and factor Xa inactivation
where is fibrinogen converted into fibrin?
active site of thrombin
does the antithrombin/heparin sulfate complex inhibit thrombin bound to fibrin?
NO
therefore thrombin is not inactivated at the site of the clot
inappropriate clot formation
thrombosis
“platelet poor” thrombosis aka “red thrombosis”
venous thromboisis
antiplatelet therapies will not be useful
“white thrombosis”
arterial thrombosis
antiplatelet therapy useful
most common cause of MI and ischemic strokes
arterial thrombosis
factor V leiden mutation
decreased control of thrombin generation (more)
