Cell Injury

Cell Injury: If the limits of adaptive response to a astimulus are exceeds, or in certain instances when the cell is exposed to an injurious agent or stress, a sequence of events follows that is loosely termed cell injury. (Ref- Robbins/ 7^th / 5)

Causes of cell injury:

1.     Oxygen deprivation:

Ø Hypoxia: Hypoxia is a deficiency of O2 to the tissue. It occurs due to cardiorespiratory failure, anaemia, CO poisoning etc.

Ø Ischemia: Means loss of blood supply from impeded flow or reduced venous drainages in a tissue.

2.     Physical agents: include mechanical trauma, extremes of temperature (burn and deep cold), Sudden changes in atmospheric pressure, radiation and electric shock

3.     Chemical agents (Poisons) and drugs: such as glucose or salt in high concentration, oxygen in high concentration, trace amount of poisons e.g- Arsenic, Cyanide, Mercuri salts etc, alcohol and narcotic drugs, increased dose of therapeutic drugs.

4.     Infectious agents: Virus, bacteria, fungi and high from parasites.

5.     Immunological reactions: anaphylactic reaction to foreign body and autoimmune disease.

6.     Genetic derangements/ Genetic errors: genetic injury may results in congenital malformations. E. g: Down syndrome, Sickle cell anaemia etc

7.     Nutritional imbalance: Such as protein-calorie deficiency, vitamin deficiency, nutritional excess etc.