(1) (hematology) One of the two initial pathways for the conversion of the prothrombin to thrombin in the coagulation cascade of hemostasis. This pathway is initiated within the blood itself or the exposure of the blood to collagen of damaged vascular wall.
(2) (cell biology) One of the two apoptotic pathways initiated by intracellular stress and involving the mitochondria.
Word origin: Latin intrinsecus (inwardly), from intrā (within) + secus (alongside).
- contact activation pathway (hematology)
- mitochondrial pathway (cell biology)