Hemostasis Flashcards
What is hemostasis?
the process of the clotting of blood and the breakdown of the clot after repair
How does the body respond to vascular injury?
vasospasm, platelets help form platelet plug, the body responds to the plug by forming fibrin mesh, followed by fibrinolysis, fibrin is then replaced by collagen
What clotting factor is most important for hemostasis?
clotting factor VIII
von Willebrand clotting factor
What are the three categories of hemostasis?
primary hemostasis, secondary hemostasis, tertiary hemostasis
What is primary hemostasis?
formation of the platelet plug
What is step one of primary hemostasis?
platelet adhesion - platelets stick to vessel walls
What is step two of primary hemostasis?
platelet activation - platelet adhesion to vessel walls causes platelets to change shape
What is step three of primary hemostasis?
platelet aggregation-formation of the primary platelet plug
If an abnormality occurs during primary hemostasis, what happens?
results in hemorrhage and prolonged bleeding
What is secondary hemostasis?
the coagulation cascade
What does secondary hemostasis result in?
formation of fibrin
What are the three pathways of secondary hemostasis?
extrinsic, intrinsic, common
What is extrinsic?
used when damage occurs outside a vessel
What is intrinsic?
used when damage occurs inside a vessel
What is the common pathway?
production of fibrin to fibrinogen
If defects occur during secondary hemostasis, what happens?
more serious bleeding than primary hemostasis
bleeding into body cavities and bruising
What is tertiary hemostasis?
formation of the plasmin
What is plasmin?
the enzyme responsible for fibrinolysis
What are acquired disorders?
occurs secondary to a disease process
What are some acquired disorders?
DIC, Erlichia, Immune-mediated thrombocytopenia (ITP), vaccine induced thrombocytopenia, drug induced thrombocytopenia, Vitamin K deficiency, toxicities
What can vitamin K deficiency be caused by?
rodenticides
What are the four most common inherited diseases?
Von Willebrand disease, Hemophilia, Canine thrombopathia, Immune mediated thrombocytopenia
