There are two main apoptotic pathways: the intrinsic and the extrinsic pathways. The intrinsic pathway, also known as the mitochondrial pathway, is triggered by internal cellular stress such as DNA damage, oxidative stress, or the presence of toxic chemicals. The extrinsic pathway, on the other hand, is initiated by external signals through death receptors on the cell surface. Both pathways eventually lead to the activation of caspases, which are proteolytic enzymes that execute apoptosis.
