Figure 2.

Coagulation cascade depicting blood clot formation. Exposure of tissue factor and subendothelial collagen post blood vessel injury triggers platelet aggregation and blood clot formation. Coagulation cascade involves conversion of inactive coagulation factor to their corresponding active form by a series of enzymatic reactions. The cascade concludes with the conversion of fibrinogen to fibrin, forming a mesh-like network with entangled blood cells and creating the blood clot. Coagulation factors are represented by Roman numerals, e.g., prothrombin is factor II (FII). When zymogens (inactivated proteases) are activated, the letter “a” is presented after the Roman numeral, e.g., thrombin is factor IIa (FIIa). As conventionally used, procoagulant and anticoagulant pathways are indicated in black and red, respectively. AT: antithrombin; HC II: Heparin cofactor II; TF: Tissue factor. (Figure courtesy of biorender.com).