Blood Coagulation Disorders Flashcards
(22 cards)
What is hemostasis?
The process that stops bleeding; includes primary (platelet aggregation) and secondary (coagulation factor) phases.
What are the two main functions of hemostasis?
Maintain fluid, clot-free blood and form plugs at sites of injury.
What are the four major components required for hemostasis?
Integrity of vessels, platelets, coagulation factors, and inhibitors.
Why is calcium essential for blood clotting?
Calcium is required for activation of several coagulation steps; blood won’t clot without it.
How do intact vs. injured endothelium affect coagulation?
Intact endothelium inhibits clotting; injury exposes tissue, activating clotting.
What disease results from small blood vessel damage due to bacteria?
Rocky Mountain spotted fever.
What is von Willebrand disease?
Autosomal dominant disorder due to deficiency of von Willebrand factor, impairing platelet adhesion.
What is DIC (disseminated intravascular coagulation)?
Abnormal bleeding due to overuse of coagulation factors; often follows viral infections (e.g., Ebola).
What do platelets release when activated?
Serotonin and platelet agonists that promote aggregation.
What is thrombocytopenia?
Decreased platelet count, caused by marrow issues, autoimmunity, or drugs.
What are petechiae?
Tiny red or blue hemorrhages due to defective/inadequate platelets.
What are the two pathways of blood coagulation?
Intrinsic (within blood) and extrinsic (initiated by tissue injury).
What is Phase 1 of coagulation?
Formation of Factor X by intrinsic or extrinsic pathways.
What happens in Phase 2 of coagulation?
Prothrombin is converted into thrombin.
What happens in Phase 3 of coagulation?
Thrombin converts fibrinogen into fibrin to form a stable clot.
What is the difference between Hemophilia A and B?
Hemophilia A = Factor VIII deficiency; Hemophilia B = Factor IX deficiency.
How is hemophilia inherited?
X-linked, typically affects males.
What role does vitamin K play in clotting?
Needed for synthesis of several coagulation factors in the liver.
What can cause vitamin K deficiency?
Antibiotics, bile duct blockage, alcoholism, newborn status.
What are two key natural coagulation inhibitors?
Antithrombin III and protein C/S system.
What does the fibrinolytic system do?
Dissolves clots by converting plasminogen into plasmin.
What activates the fibrinolytic system?
It is activated simultaneously with coagulation to ensure balance.
