Cell commits suicide by apoptosis.
Cellular homicide is necrosis
Apoptosis (from Ancient Greek word “falling off”) is a process of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death.
Physiologic causes:
1)The programmed destruction of cell during embryogenesis. It is programmed because it is death of specific cell types at defined times during development.
2)Hormone-dependent physiologic involution, such as involution of the endometrium during the menstrual cycle.
3)Cell deletion in proliferating cell population, such as intestinal crypt epithelium
4) Death of cells that have served there useful purpose, such as neutrophils in an acute inflammatory respone.
5) Elimination of potentially harmful self reactive lymphocytes.
Pathological causes :
Cell death produced by a variety of mild injurious stimuli like
– heat, radiation, cytotoxic cancer drugs, etc.
that cause irreparable DNA damage that in turn triggers cell suicide pathways.
2) Cell injury in certain viral diseases such as viral hepatitis.
3) Cell death in tumors.