Discuss the similarities and differences between the two types of cell death, Necrosis and Apoptosis.
Both necrosis and apoptosis are the two types of cell death than can occur when a cell has undergone harm or disease. Necrosis is an uncontrolled process in which there is a complete breakdown of cellular homeostatis with a large unco-ordinates breakdown of all cellular constituents. Necrosis can occur due to many factors such as an infection or failure of blood supply (ischemia). Examples of necrosis can includes Fat necrosis (seen in patients with breast cancer), Caseous necrosis and coagulation necrosis (common in TB patients). On the other hand, Apoptosis is a controlled process, which is often referred to as ‘programmed cell death’ and involves the cell undergoing a sequence of events to eliminate harmful cells without releasing harmful substances to the area. Apoptosis can undergo 2 pathways, the intrinsic and extrinsic pathway.
When looking at the morphological features related to necrosis, compared to that of apoptosis, it can be seen that necrosis has a loss of membrane integrity, and the uncontrollable process eventually eats away at the cells core membrane, whilst apoptosis deals with the membrane by ‘blebbing’ the plasma, yet leaving the membrane in tact. No vesicle’s are formed for necrosis compared to apoptosis where there are some membrane bound vesicles. Necrosis undergoes total lysis (death) and the term ‘karylolysis’ is given for when the cells nucleus dies, although apoptosis is known to be a programmed form of cell death, the mechanisms highlight that the cells are fragmented into smaller bodies and the body naturally removes them, without causing an inflammatory response, compared to necrosis where an inflammatory response is created.
Biochemical features include the need of ATP for apoptosis to occur, yet necrosis can happen freely without any form of energy supplied. DNA is randomly digested and the death is some what ‘random’ and unorganised, affecting neighbouring tissue (secondary), whilst that of apoptosis involves oligonucleosomal fragmentation of DNA, penetrating the nuclesome rarther that digestion. The intrinsic mechanism of apoptosis shows the release of cytochrome C to occur by cytoplasm, eventually helping the cell, where as necrosis produces no beneficial products after performing cell death.
To conclude, both necrosis and apoptosis are forms of cell death. Whilst one is an uncontrollable process, involving random and lethal harm to cells and surrounding tissues, one is somewhat ‘programmed’ and benefits the cells by removing those that have been affected by an injurious stimuli (such as an infection of lack of blood). Necrosis is a ‘messy’ process producing gross matter, whilst apoptosis releases useful content back into the body. Morpholical and biochemical features are highlight the main differences between both forms of cell death, and as these continue to be performed silently within our body, they can cause either good, or bad consequences.