Blood coagulation cascade and platelet activation (None)

The blood coagulation cascade and platelet activation refer to interrelated biological pathways vital for hemostasis, or the prevention of bleeding at sites of vascular injury. Hemostasis consists of two major stages: primary hemostasis, involving platelet activation, adhesion, and aggregation; and secondary hemostasis, involving a cascade of serine proteases (clotting factors) that generate and stabilize a fibrin clot. Platelets are activated at injury sites, interacting through receptors such as glycoprotein IIb/IIIa (binds fibrinogen) and P2Y12 (ADP receptor), which facilitates aggregation[1][2][3]. The coagulation cascade involves either the intrinsic or extrinsic pathway, both leading to the common pathway to generate thrombin and fibrin[4][5][6][7]. The tightly regulated balance between clot formation and dissolution ensures rapid wound closure while minimizing the risk of pathological clotting (thrombosis). Dysregulation underlies a range of disorders from hemophilia (bleeding) to thrombosis (strokes, myocardial infarctions, pulmonary embolism). Numerous drugs target enzymes and receptors across these pathways for therapeutic anticoagulation or anti-platelet effects. Importantly, "blood coagulation cascade and platelets" is not a specific molecular target, but a system-level process incorporating many individual protein targets and cell types, and thus should not be treated as a singular molecular entity.

Other names

Coagulation cascadeBlood clotting pathwayHemostasis systemPlatelet activation pathway

Inhibition of clotting factor synthesis (e.g., warfarin inhibits vitamin K-dependent factors) Direct inhibition of factor Xa or thrombin (e.g., rivaroxaban, dabigatran) Inhibition of platelet activation/aggregation (e.g., aspirin inhibits COX-1, clopidogrel blocks P2Y12 receptor, abciximab blocks glycoprotein IIb/IIIa) Enhancement of antithrombin activity (e.g., heparin) Promotion of fibrin clot breakdown (e.g., plasmin activation by fibrinolytics)