Atrophic Factor

Atrophic Factor

Programmed cell-death (or PCD) is death of a cell in any form, mediated by an intracellular program. PCD is carried out in a regulated process, which usually confers advantage during an organism's life-cycle. For example, the differentiation of fingers and toes in a developing human embryo occurs because cells between the fingers apoptose; the result is that the digits are separate. PCD serves fundamental functions during both plant and metazoa (multicellular animals) tissue development. Apoptosis and autophagy are both forms of programmed cell death, however necrosis is a non-physiological process that occurs as a result of infection or injury.

Necrosis is the death of a cell caused by external factors such as trauma or infection and occurs in several different forms, not a form of PCD as previously stated.