LG2.14 Introduction to Coagulation Part 1 Flashcards
What are the 4 major events that occur in hemostasis?
1) Vasoconstriction
2) Platelet Actions: Adhesion, Activation, Release or Secretion, Aggregation
3) Fibrin Clot formation/coagulation
4) Fibrinolysis
What is hemostasis?
Hemostasis is the process of normal blood clotting, the subsequent dissolution of the clot, and subsequent repair of the injured tissue.
What are the major components of the hemostatic system?
a. Vascular endothelium
b. Platelets
c. Coagulation system
d. Fibrinolytic system
What does Nitric Oxide do?
Inhibits platelet adhesion and aggregation by elevating levels of cGMP
What does Prostacyclin do?
Inhibits platelet aggregation by increasing levels of cAMP
What does Thrombomodulin do?
Binds thrombin which then cleaves protein C to yield activated protein C
What substances does the Endothelial cells produce that are potent vasodilators and inhibitors of platelet functions?
- prostacyclin (prostaglandin I2, PGI2)
- nitric oxide (NO).
What does Tissue Plasminogen activator (TPA) do?
Activates fibrinolysis
What is Primary Hemostasis?
Formation of a Platelet Plug
What is the steps of Primary hemostasis?
i. Platelet Adhesion
ii. Shape change
iii. Granule release (ADP,TXA2)
iv. Recruitment
v. Aggregation (hemostatic plug)
What is secondary hemostasis?
Formation of a fibrin Clot
What is the steps of secondary hemostasis?
i. Tissue factor
ii. Phospholipid complex expression
iii. Thrombin generation
iv. Fibrin polymerization
What is Prothrombin converted to?
Thrombin
What is thrombin covert?
Fibrinogen to Fibrin
What is the function of vWF?
function is binding to other proteins, in particular factor VIII, and it is important in platelet adhesion to wound sites.[1]