Unformatted text preview: icide and removal caused by specific gene
activity Apoptosis is rapid individualized cell death controlled by specific gene activity.
Cells kill themselves in apoptosis by activating a specific genetic control pathway.
Apoptosis is a highly-regulated process triggered by release of cytochrome c from
mitochondria and activation of DNA endonucleases and specific proteases (called
caspases) which degrade chromatin and cytoplasmic proteins, respectively. So cytoskeleton
Fig. 3-19 comes apart
and cell shrinks
into NOTHING. Apoptotic cell loses cell junctions and chromatin condenses (pyknosis). The apoptotic
nucleus and the cell shrink, forming one or many apoptotic bodies. These do not break
up and release their contents, but are engulfed (phagocytosis) by other cells. Apoptosis = NORMAL. very minor, no inﬂammatory response, very rapid.
Necrosis = WHEN CELL IS INJURED. cell proteins gets released, cell bursts open! this is BAD -- inﬂammatory response is stimulated. inﬂux of WBCs…
…can be a very damaging process. It is important to distinguish apoptosis from cellular
necrosis, which is death due to some form of tissue
Necrosis results in release of cellular proteins, etc.
which elicit an inflammatory response in th...
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