Figure 2.

Classical Coagulation Cascade with Crosstalk. Clot formation as activated through the extrinsic pathway (red), intrinsic pathway (blue) and the common pathway (green). Crosstalk and feedback between pathways is shown in blue if positive and red if negative. Factors are indicated with a roman numeral and an “a” if activated. Abbreviations: Ca²⁺, calcium ions; FBGN, fibrinogen; HMWK, high-molecular-weight kininogen; PL, platelet membrane phospholipid; PK, prekallikrein; TF, tissue factor; TFPI, tissue factor pathway inhibitor.