(1) (hematology) One of the two initial pathways for the conversion of the prothrombin to thrombin in the coagulation cascade of hemostasis. The pathway is initiated by a trauma to the vascular wall or a trauma to extra-vascular tissues.
(2) (cell biology) One of the two apoptotic pathways identified by bypassing the mitochondria, direct activation of caspases, and the binding of extracellular ligands to initiate specific pro-apoptotic receptors on the cell surface.
Word origin: Latin extrinsecus (from without, without, on the outside)
- tissue factor pathway (hematology)