Causes of cell injury
Car accidents are an example of gross physical injury to cells, but subtle internal abnormalities, such as genetic mutations that prevent production of a vital enzyme, are also possible causes.Oxygen deprivation
A hypoxic state results in reduced aerobic oxidative respiration, which results in cell injury. An extremely common and important cause of cell death and injury is hypoxia. Anemia in particular causes hypoxia, as do carbon monoxide poisoning and diminished oxygen-carrying capacity of the blood. Hypoxia is also caused when there is reduced blood flow (celled ischemia), inadequate oxygenation due to cardiac or respiratory failure, and severe blood loss. Cells may become injured, die, or adapt to a hypoxic state, depending on its severity. In arteries, for example, a narrowing of the vessel may initially cause atrophy of the tissue, while more severe hypoxia might lead to injury and cell death.Physical agents
Among the physical agents capable of causing cell injury are mechanical trauma, radiation, extreme temperature, sudden fluctuations in atmospheric pressure, and electric shock.Chemical agents and drugs
There is no comprehensive list of chemicals that can cause cell damage. Hypertonic concentrations of glucose or salt can cause cellular damage directly or by derangement of electrolytes. High concentrations of oxygen are toxic as well. Arsenic, mercury salts, and cyanide, in addition to recreational drugs, we are exposed every day to environmental and air pollution, insecticides and herbicides; industrial and occupational hazards and ever-growing quantities of therapeutic drugs. among other poisons, can kill cells in a matter of minutes or hours if trace amounts of them are present.Immunologic reactions
Immune responses play an essential role in countering infectious pathogens, but they can also cause cell damage. Several autoimmune diseases are triggered by the immune system's reaction to endogenous self-antigens. A number of external agents, including bacteria and environmental materials, can also cause injury to cells and tissues.Infectious agents
Submicroscopic viruses and large tapeworms are all part of these agents. The rickettsia, bacteria, fungi, and higher forms of parasites fall between these two categories. These agents produce injuries in a variety of ways.Nutritional imbalances
Cell injury is still mainly caused by nutritional imbalances. A staggering number of deaths are caused by protein-calorie deficiencies, primarily among underprivileged populations. Around the world, many people suffer from vitamin deficiencies. Nutritional problems can occur as a result of self-induced starvation (anorexia nervosa). Additionally, nutritional excesses have played a big role in cellular damage. The increased incidence of some diseases is associated with obesity and excess cholesterol, such as atherosclerosis and diabetes. A number of diseases, including undernutrition and overnutrition, are associated with the composition of the diet.Genetic derangement
In the order described, genetic abnormalities can result in defects ranging from the severity of congenital malformations associated with Down syndrome, which are caused by chromosomal defects, to the subtlety of sickle cell anemia, which occurs when a single amino acid is substituted in hemoglobin. A genetic defect may cause cell death when the body lacks functional proteins, such as enzyme defects in metabolic errors, or the body accumulates damaged DNA or misfolded proteins, which can cause cell death if they are unable to be repaired. Chemicals and other environmental insults can also impair a cell's durability because of genetic variations.Pathogenesis
Numerous factors can lead to cellular damage. Here, oxygen plays an important role in the injury process. The mechanisms by which cells are injured are:
Hypoxia and ischemic cell injury
Cell membrane damage
Cells can be damaged by destructive physical agents like heat or radiation, which cook or coagulate their contents.When nutrients are inadequate, such as oxygen or glucose, or ATP isn't produced properly, the cells may lack essential materials to survive.
Mitochondrial damage
Calcium and inorganic phosphate levels increase with an increase in cytosolic calcium.Inorganic phosphates and fatty acids by themselves do not cause mitochondrial damage, but when combined with high Ca2+ they are extremely detrimental. Calcium alone can still cause mitochondrial damage.
Nuclear damage
Furthermore, decreased cellular ATP levels and an increase in adenosine monophosphate (AMP) cause phosphofructokinase glycolysis to be activated in order to maintain cellular energy by converting glycogen into ATP. If oxygen is restored, this stage can be reversed.- An unpaired electron in outer orbit of a free radical defines it as a chemical species. They catalyze chemical reactions.
- Reperfusion of ischemic cells causes this condition. Chemical injury, cellular aging, hyperoxia, killing of exogenous biological agents, destruction of tumor cells, inflammation damage, chemical injury, ionization, and atherosclerotic plaque all contribute to arteriosclerosis.
- Several radicals can be destructive to the body, including superoxide radicals, hydroxyl ions, and peroxide ions, which can damage lipids, proteins, DNA, and cytoskeletons.
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