What is the Injury of the Cell or Cells: Apoptosis and Necrosis
Introduction:
Cell injury is the cell's inability to adapt or the cell's failure to adapt under pressure.
There are two parts of cell injury, the first section is the affected cells that are able to recover or treat from an injury called reversible, either with regard to the second section the affected cells are unable to recover or cure, and we notice that the two sections are opposite called irreversible. An example of a reversible there is morphological changes responding to a stimulus if the stimulus is removed. It is the presence of large amounts of cytoplasmic water because of the cells are unable to balance or maintain ion balance and fluids. As previously mentioned, a change in the hydrophilic result is due to ischemia. When the cells lack blood flow, this leads to a decrease in oxygen transported into the cell and leads to problems and depletion in ATP. There is also what is called a loss of oxidative phosphorylation. This may lead us to a reduction in ATP distribution and the preference of sodium and potassium in the pump, increased potassium outside the cell and. An increase in water and sodium on the inside of the cell leads to what is called cell swelling. The second type of cell injury, which is called to irreversible it, it is the devastating and severe injury that leads to the death of the cells. The second type, the injury of cells is irreversible and may lead to mitochondrial damage, reduced levels of ATP distribution, and cellular membrane damage. There are two types of cell injury that are irreversible, which are programmed cell death called apoptosis and unprogrammed cell death called necrosis. Programmed cell death (apoptosis) leads to cellular contraction, cell fragmentation, and cell phagocytosis. As for unprogrammed cell death ( necrosis), it is more dangerous and leads to cellular swelling, protein denaturation, destruction of the cell membrane, and digestion. Cell necrosis is that irreversible cells are damaged by stimuli, which in these cells may lead to cell or cell death. The factors that contribute to irreversible cell death are infections that include (fungi, parasites, viruses, and bacteria). Cell necrosis blocks the oxygen and denies it access to the cell, which is transported by the blood to the cells. There are five types of cell necrosis: caseous necrosis, coagulative necrosis, gangrene necrosis, liquefied necrosis, and fat necrosis. Gangrene necrosis is one of the most serious diseases that may affect people. It affects hands, fingers, and legs, or in general, it affects the upper and lower extremities. The appearance on a person with gangrene necrosis is skin that takes a black color, with varying degrees of rot, which may affect the person. Gangrene has three types: dry gangrene, wet gangrene, and gaseous gangrene.
Mechanisms of cellular injury:
The death of a cell or cells is an important thing for humans, it has the benefit of destroying and removing dead and infected cells or cells that are not needed. We add, therefore, that cell death has important benefits in terms of species, as it provides a mechanism to eliminate people with poisoning. The cell is infected by its subsequent damage, and it may be chemical or physical. The responses to cellular injury fall into four types: heat shock, ischemia, oxidizing and acute phase response.
Mechanisms involved in necrosis cells:
1- Decrease ATP due to ( multiple downstream effects)
2- Mitochondrial damage due to ( leakage of proapoptotic proteins )
3- Entry of calcium due to ( mitochondrial permeability and Activation of multiple cellular enzymes )
4-increase ROS due to (damage to lipids, proteins, and DNA)
5- Membrane damage due to
- A- plasma membrane due to ( loss of cellular component )
- B - Lysosomal membrane due to ( Enzymatic digestion of cellular components)
6- Protein misfolding and DNA damage due to ( Activation of proapoptotic proteins)
Apoptosis is programmed cell death, or that means dead or damaged cells in the human body. It differentiates them from cell necrosis. Cell necrosis is the death of unprogrammed cells. In biology, it means eliminating damaged cells.
Mechanism of apoptosis:
means morphological changes that lead to shrinkage of cell sizes and shapes, and DNA cracking, superficial, phagocytic.
There are differences between cell necrosis and cell apoptosis: cell necrosis leads to inflammation, while cell apoptosis does not lead to inflammation, cell necrosis leads to damage of the membrane, the apoptosis does not damage the membrane, cellular necrosis does not have apoptotic bodies, and cellular apoptosis is the formation of apoptotic bodies.
In TUNEL staining :
- Necrosis cells are negative.
- Apoptosis cells are positive.
Conclusions:
In the end, we talk about the outcome. When the cell dies or is damaged, the human body will attempt to repair damage and repair, replacing the dead cells with live cells to continue normal functions. If the cell dies completely, the body replaces the dead cell with a live cell and removes the dead cell, or it is instead of the cells. For example, you can replace the dead cell with connective tissues in order to provide protection and full support to the surviving cells. Reform We can describe it in one sentence, which is to bridge the gap for dead cells. Damaged or dead cells cannot return again because they are not able to be living cells again. The solution here is non-sexual reproduction, which is the right thing to do. When the body cannot reproduce asexually, there is another substitution. The substitution is that a dead cell is replaced as we mentioned previously with connective tissue to maintain and provide support and protection to other cells.
Reverence :
- http://medinfo.ulf.edu/pa/chuck/fall/handouts/injury.ht
- http://www.ephonline.org/docs/1994/suppl-/farber.html
- http://en.wikipedia.org/wiki/apoptosis
