Apoptosis

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Apoptosis
An etoposide-treated DU145 prostate cancer cellexploding into a cascade of apoptotic bodies. The sub images were extracted from a 61 hour time-lapse microscopy video, created using quantitative phase-contrast microscopy. The optical thickness is color-coded. With increasing thickness, color changes from gray to yellow, red, purple and finally black.[1]  See the video at The Cell: An Image Library
Anatomical terminology

Apoptosis (/ˌæpəˈtoʊsɪs/;^[2][3] from Ancient Greek ἀπό apo, "by, from, of, since, than" and πτῶσις ptōsis, "fall") is the process of programmed cell death (PCD) that may occur in multicellular organisms.^[4] Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation.

In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, in general apoptosis confers advantages during an organism's lifecycle. For example, the separation of fingers and toes in a developing humanembryo occurs because cells between the digits undergo apoptosis. Unlike necrosis, apoptosis produces cell fragments called apoptotic bodies that phagocytic cells are able to engulf and quickly remove before the contents of the cell can spill out onto surrounding cells and cause damage.^[5]

Between 50 and 70 billion cells die each day due to apoptosis in the average human adult. For an average child between the ages of 8 and 14, approximately 20 billion to 30 billion cells die a day.^[6]

Research in and around apoptosis has increased substantially since the early 1990s. In addition to its importance as a biological phenomenon, defective apoptotic processes have been implicated in a wide variety of diseases. Excessive apoptosis causes atrophy, whereas an insufficient amount results in uncontrolled cell proliferation, such as cancer. Some factors like fas, caspases (C-cysteine rich, asp- aspartic acid moiety containing, ase - proteases) etc. promotes apoptosis and bcl 2 inhibits apoptosis.