Hemastasis Basics
These are the three components of Virchow's Triad?
What is blood flow, BV wall, and coagulability of the blood?
This factor mediates platelet adhesion to exposed collagen.
What is von Willebrand factor (vWF)?
This factor is where the intrinsic and extrinsic pathways merge into the common pathway.
What is Factor X?
This platelet disorder is defined as a platelet count below 100,000/µl.
What is thrombocytopenia?
This drug is a Vitamin K analogue that inhibits Vitamin K recycling, requiring regular monitoring and contraindicated in pregnancy.
What is warfarin?
This is the term for inappropriate/pathologic coagulation.
What is thrombosis?
These two substances are released in the platelet release reaction to recruit/activate other platelets.
What are ADP and thromboxane A2?
This lab test measures the extrinsic pathway and is prolonged by warfarin use.
What is Prothrombin Time (PT)?
This autoimmune disorder involves IgG antibodies targeting platelet glycoproteins, causing sequestration and destruction of platelets.
What is immune (idiopathic) thrombocytopenic purpura (ITP)?
This drug binds lysine on antithrombin III, accelerating inactivation of XIIa, XIa, IXa, Xa, and IIa — and is safe in pregnancy.
What is heparin?
This protein network, in which formed blood elements are trapped, defines a clot.
What is fibrin?
This immediate vascular response to injury occurs within seconds to minutes, driven by pain receptor stimulation and endothelin release.
What is vascular spasm (vasoconstriction)?
This lab test measures the intrinsic pathway and is prolonged by heparin use, normally 25–35 seconds.
What is Activated Partial Thromboplastin Time (aPTT)?
This thrombotic microangiopathy causes platelet aggregation, microthrombi, and (in females only) deep peripheral ischemia.
What is thrombotic thrombocytopenic purpura (TTP)?
This antiplatelet drug irreversibly inhibits cyclooxygenase, blocking thromboxane A2 production;
+200 BONUS if you can name the syndrome caused when this drug is overused in children with viral illness.
What are aspirin and Reye's syndrome?
This enzyme dissolves a clot by digesting fibrin and inactivating fibrinogen, prothrombin, and factors V, VIII, and XII.
What is plasmin?
The 3 steps of platelet plug formation, in order.
What is platelet adhesion, platelet release action (ADP and TXA2), and platelet aggregation?
Factor XIIIa performs this action on soft fibrin clot to convert it into a hard, stable clot.
What is cross-linking of fibrin?
This complex acquired disorder involves simultaneous clotting and hemorrhage, often triggered by sepsis, cancer, or trauma.
What is Disseminated Intravascular Coagulation (DIC)?
This class of drugs blocks the final common pathway of platelet aggregation by antagonizing the receptor that binds fibrinogen.
What are Glycoprotein IIb/IIIa antagonists?
This hemostatic plug is self-limiting in size and duration, specifically localized to the site of bleeding, and persists only long enough to allow cellular repair before being removed by this process.
What is thrombolysis?
This structural component reinforces the platelet plug, formed during the clotting process.
What are fibrin threads?
These are the clotting factors present in the intrinsic pathway.
What are XII, XI, IX, VIII?
This X-linked deficiency of Factor IX is also known as "Christmas Disease."
What is Hemophilia B?
This drug promotes clot lysis by converting plasminogen to plasmin and is used IV to relieve coronary artery occlusion.
What is tissue plasminogen activator (t-PA)?