apoptosis

apoptosis /ap·op·to·sis/ (ap″op-to´sis) a pattern of cell death affecting single cells, marked by shrinkage of the cell, condensation of chromatin, and fragmentation of the cell into membrane-bound bodies that are eliminated by phagocytosis. Often used synonymously with programmed cell death. apoptot´ic

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ap·op·to·sis (pp-tss, p-t-)

n.

A natural process of self-destruction in certain cells that is determined by the genes and can be initiated by a stimulus or by removal of a repressor agent. Also called programmed cell death.

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apoptosis

[ā′pōtō′sis, ā′poptō′sis]

Etymology: Gk, apo, away, ptosis, falling

necrosis of keratinocytes in which the nuclei of the necrotic cells dissolve and the cytoplasm shrinks, rounds up, and is subsequently phagocytized. The term generally refers to "programmed" cell death.

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apoptosis (a·pp·tōˑ·sis),

n programmed destruction of cells; mechanism that keeps cell numbers in check by eliminating senescent cells or those without useful cell function.

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apoptosis (ap´tō´sis),

n cell reduction by fragmentation into membrane-bound particles that are phagocytosed by other cells.

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apoptosis

programmed cell death, a process including coagulative necrosis and shrinkage.

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apoptosis 

A process of single cell death, which consists of a series of biochemical events including cell shrinkage, condensation of chromatin, formation of cytoplasmic blebs and fragmentation of nuclear DNA into membrane-bound particles that are phagocytosed by other cells. It is an important physiological process that helps keep the number of cells relatively constant by compensating for mitosis. It is necessary to prevent either uncontrolled growth and tumour formation (as may be caused by genetic mutation), or hypotrophy (as in ischaemia) due to excessive apoptosis induced by a stimulus, such as irradiation, toxic drugs, etc. Apoptosis represents a form of programmed cell death. Example: almost all corneal epithelial cells die within 10 days, and are replaced by mitosis. See mitosis; neuroprotection.