NECROSIS
• The cell death due to tissue damage is called necrosis.
• During necrosis the typical cell swells and bursts, releasing the intra, -cliular contents, which can damage neighboring cells and cause inflammation
APOPTOSIS
• Normally the death of the cell is programmed.
• Internal program of events and sequence of morphological changes by which cell commit suicide is collectively called as apoptosis (Greek word that means dropping off or falling off).
• During this the dying cells shrink and condense ultimately split up, thus release small membrane founded apoptotic bodies, which are generally phagocytosed by other cells.
Intracellular constituents are not released freely and the surrounding cells are not affected.
• Programmed cell death helps in proper control of multi-cellular development, which may lead to deletion of entire structure (e.g., the tail of developing human embryos) or part of structure (e.g., tissue between developing digits).
• Cell death even controls the number of neurons, because most of the neurons in the human body die during development. Cell death in multi-cellular organisms is controlled by two different ways:
i) The cell commit suicide in the absence of survival signals (trophic factors).
The cells are murdered by killing signals from other cells.