Flashcards in Hemostasis Deck (33):
What are the major players in hemostasis?
What are the three things that contribute to thrombosis?
Abnormal blood flow
Hypocoagulation is displayed as:
Hypercoagulation is displayed as:
Hemostasis and coagulation are regulated by what 3 componenets?
Vascular wall: endothelial cells have procoagulant and anti-coagulant on them
What are the steps of hemostasis?
Vasoconstriction: very transient and fast
Primary hemostasis: hemostatic plug formed; reversible
Secondary hemostasis: polymerizes fibrin; irreversible
What is the endothelial derived vasoconstrictor that follows injury to vessel wall?
What two things initate the coagulation cascade at secondary hemostasis?
Tissue Factor (F3) + activated platelets
What are some properties of endothelial cells that are prothrombotic?
Antifibrinolytic properties: prevents fibrinolysis
What are some properties of endothelial cells that are antithrombotic?
Have heparin like modules
Thrombomodulin binds thrombin
Tissue factor pathway inhibitor: deactivates TF, F7 and F10
What is it again that resists shear forces?
vWF and GP2a
What are the three pathways of the coagulation cascade?
What is the extrinsic pathway?
Starts with Factor 3 (Tissue factor)
Activates F7 --> F10 (Common pathway) AND F9 (Intrinsic)
What is the intrinsic pathway?
Factor 12 --> Factor 11 --> F9 --> F8 (co-factor) --> F10 (Common)
What is the common pathway?
F10 --> F5 --> F2 (thrombin)
Cats often lack what factor?
Factor 12; not a big deal as F7 can still activate the intrinsic pathway via F7 --> F9
What are the vitamin K dependent factors?
Factors 2,7,9,10 Protein C and Protein S
PT test looks at what? What % has to be decreased for this to prolong test?
Extrinsic and common pathways
>70% of factors have to be decreased
T/F If not available, human reference intervals are okay to substitute for PT and PTT tests
FALSE; they should NEVER be used
PTT test looks at what?
Intrinsic and common pathways
D-Dimers test is a specific indicator for what?
What is an increased D-Dimers indicate?
Hemorrhage and thrombosis
What species can a D-Dimers test be run for? Which should it not be run for?
Dogs and horses
Don't use in cats
What are FDPs? When do we see an increase in these?
Fibrin degradation products
Increased in DIC, inflammation and liver DZ
What factors play a role in fibrinolysis?
tissue Plasma Activator (tPA)
Protein C and S
Tissue Factor Inhibitor
Antithrombin III is a protein that inhibits what?
Factors 7, 11, 9, and 10
Proteins C and S inhibit what?
Factors 7 and 5 (co-factors)
Hemophilia A is a deficiency in what?
Factor 8; affects the intrinsic pathway
Hemophilia B is a deficiency in what?
Hageman's disease is a deficiency in what factor?
Factor 11 deficiency can be seen in what species?
Dogs and Holstein cattle
How does Factor 7 deficiency present?
Likely in dogs with easy bruising
T/F Disseminated Intravascular Coagulation is a primary disease
FALSE; it is secondary to other pathology