haemostasis Flashcards
primary haemostasis?
formation of platelet plug
2y haemostasis?
fibrin clot
platelet lifespan?
7 - 10 days
endothelial wall damage exposes?
collagen and releases von willebrand factor
platelet adhesion at site of injury
secretion of various chemicals by platelets which leads to aggregation
failure of platelet plug formation, causes?
vascular, platelets (reduced number - thrombocytopenia)
reduced function
von Hillebrand factor
consequences of failure of platelet plug formation?
EASY BRUISING epistaxes, gastrointestinal, conjunctival, menorrhagia
can also get inter cranial haemorrhage and retinal haemorrhage
y
secondary clot formation - what 2 things involved in initiation?
TF and VIIa
propagation?
v an xa
amplification?
thrombin -> VIII/IXa ->V/Xa
failure of fibrin clot either?
hereditary - haemophilia - single cutting factor deficiency
multiple clotting factor deficiencies?
DIC
increased fibrinolysis?
usually part of complex coagulopathy
what breaks down fibrin to FDPs?
plamin
what activates plasminogen?
tissue plasminogen activator
haemophilia 1 is absence of VIII
haemophilia 2 is absence of factor IX
what kind of inhibitor is anti thrombin III?
serine protease inhibitor
what does thrombin bind to which activities protein c and protein s, which then inhibit v/xa and viii/ixa
thrombomodulin
what is thrombophilia?
lOw anticO Deficiency of naturally occuring anticoagulants may be hereditary
increased tendency to form venous thrombosis
y
most common thrombophilia?
factor 5 leydig
platelets made from?
megakaryocytes
factor 5 leydig. causes an increase in ?
clotting. factor 5 leydig is a mutant variant of factor 5
