Pathophysiology of Cell Injury
Trauma is a physical injury. Physical disruption of cells is results to cellular injury or damage. Trauma can be caused by the following factors:
Hypothermia is defined as a decreased in the body temperature. Extreme cold injures the cells as a result of ice crystal formation in the water of the cytoplasm. Typically, this damage is noted on frostbite.
Hyperthermia is the opposite of hypothermia wherein there is an increased in the body temperature. Extreme heat damages the cells by disrupting the cell proteins. Presence of excessive heat causes the proteins of the cells to denature. Normally, the function of a cell’s protein is linked to their structure, thus when denaturation occurs it is followed by a significant functional cell disruption. In very extreme heat such as in burn injury, protein is chemically transformed by combining with oxygen. The product of this transformation is the blackening and charring characteristic of a burned tissue.
- Ionizing radiation
Ionizing radiation is a high-energy radiation that is associated with x-rays and nuclear radioactivity. Very high exposures to ionizing radiation produce temperature elevation in the tissues that can result to burning. Aside from the mentioned information, ionizing injury can also cause injury through the production of free radicals. Free radicals are highly energetic ions that are produced and formed when ionizing radiation strips down the electrons from the cells.
- Mechanical pressure
Mechanical pressure can result to cellular trauma or injury. When cells are faced with increasing pressure, cells are physically overwhelmed and they cannot maintain their structural integrity. In cases where a pressure is applied to a certain body surface or a pressure is created due to the presence of a rapidly expanding tumors adjacent cells are subject to trauma or injury. Even without touching, cells can be injured mechanically. When loud noises are heard high pressures are generated to the fluid of the delicate inner ear that can cause injury.
The action of microorganisms can cause not only intoxification or poisoning but also physical trauma. Viral proteins are formed when viral infection takes place. Viral proteins then bind to the cell membrane which results to gap formation that prevents normal cell operation causing cell rupture.
- Immune system defect
Antigen-antibody interactions at cell surfaces can lead to the physical disruption of the cell membrane. This occurs when the newly formed viruses are released from the cell without damaging it and some of their viral proteins are incorporated into the plasma membrane of a normal cell. Specialized cells in the immune system recognize the viral proteins attached to the cell membrane of a normal cell as foreign. The cells of the immune system then attack the foreign substances by binding with the viral proteins which results to membrane injury or damage and cellular death.