What Are Some Causes Of Cell Injuries?

Following are some causes of cell injuries:
1 Hypoxia: It refers to reduction of oxygen supply to tissues below physiological levels. It causes cell injuries by inhibiting oxidative phosphorylation in mitochondria
Causes of hypoxia:
1Inadequate oxidation of blood  
2 loss of oxygen carrying capacity of blood e.g. anemia, carbon-monoxide
3 loss of blood supply to tissues, that is ischemia (due to obstruction to arterial flow or venous drainage by vascular disease)
4 loss of oxygen utilizing capacity of cell (due to inactivation of cytochrome oxidase by cynaide)
2 Immune reactions (mediated by antibodies or T- cells) cause cell injuries in two ways:
(A) hypersensitivity reactions (or disease):here cell injury is mediated by antibodies or T-cells directed against exogenous (non-self) antigens, e.g. resin of poison ivy
(B) auto-immune diseases: here cell injury is mediated by antibodies or T- cells directed against endogenous (self) antigens, e.g. systemic lupus erythematosus

3 Chemicals and drugs:
(A) innocuous (harmless) substances e.g. glucose in high concentration , cause cell injury by deranging osmotic environment of cells
(B) Poisonous (toxins) and drugs e.g. mercuric chloride, cause cell injury by interfering with cell's vital functions. Such as membrane permeability, osmotic homeostasis or integrity of enzyme or cofactor