The Cytoplasm Also Sinks And The Plasma Membrane Bubbles Out And Separate

The cytoplasm also sinks and the plasma membrane bubbles out and separate nodules are formed containing cellular organelles (Lavin and Watters, 1993). These separate nodules break off at a certain point and are engulfed by neighbouring phagocytic cells. There is no spillage, rupture of cell membrane or inflammation. Apoptosis represents the body's natural way of facing cell death so no negative signals or damage of whole tissue areas is seen. Here cell death occurs not due to toxins or unnatural means but simply due to a lack of receiving survival signals. Necrosis represents unnatural cell death with inflammation. Apoptosis represents natural cell death without any inflammatory response.
There are other processes by which cells are destroyed. One of them is autophagy. This occurs when there are inadequate nutrients within the cell and certain organelles within the cell body have to be used up for reuse of the components within the organelle. Double membranes form within the cell, the material marked is engulfed and an autophagosome is formed which fuses with the lysosome and the hydrolytic enzymes then degrade the materials.

NECROSIS

APOPTOSIS

Research Evidence on Cell Death
In a study on cell death, Majno and Joris (1995) reviewed the historical development of cell death and traced the origin of terms necrosis, coagulation necrosis, autolysis, physiological cell death and programmed cell death as also chromatolysis, karyorhexis, karyolysis and cell suicide. According to the authors there are three forms of cell death, by lysosomes, free radicals and genetic mechanism as in apoptosis. In contrast to blebbing and zeiosis typical features of apoptosis include budding, and the typical feature of necrosis, i.e. inflammation is also discussed. Cell death is categorised into two major divisions in this paper, either programmed cell death as in apoptosis or accidental cell death as in necrosis.
According to the authors, necrosis however is an incorrect term for cell death as it can indicate changes secondary to cell death which occurs only by apoptosis. So according to Majno and Joris, whereas apoptosis indicates primary cell death, necrosis refers to associated and secondary changes that follow apoptosis. Some suggest this as secondary necrosis which sees necrosis not as a different kind of cell death but a category only secondary to the main kind of cell death, namely apoptosis. One type of accidental cell death highlighted by Majno and Joris is Ischemic Cell death which is a category of its own caused mainly by a failure of ionic pumps of the plasma membrane. Ischemic cell death is accompanied by swelling and thus it is not called apoptosis but oncosis, derived from onkos, means 'to swell'.