Cell injury refers to the structural or functional impairment of a cell resulting from exposure to harmful stimuli or stressors.
It can disrupt normal cellular processes and lead to cell dysfunction or death.
Types of Cell Injury
1. Reversible Cell Injury:
If the harmful stimulus is removed or is mild, the cell can recover and regain normal function.
Reversible injury often involves:
Cellular swelling
Fatty changes
Minor structural alterations
2. Irreversible Cell Injury:
If the harmful stimulus persists or is severe, irreversible injury occurs, leading to cell death.
This can manifest as:
Programmed cell death (apoptosis)
Uncontrolled cell death (necrosis)
Causes of cell injury:
Physical agents: Mechanical trauma, extreme temperatures, radiation, or electrical injury.
Chemical agents: Toxic chemicals, heavy metals, drugs, poisons, or environmental pollutants.
Infectious agents: Bacteria, viruses, fungi, or parasites.
Immunological reactions: Autoimmune diseases or hypersensitivity reactions.
Genetic factors: Genetic mutations, chromosomal abnormalities, or inherited conditions.
Nutritional imbalances: Deficiencies or excesses of essential nutrients.
Hypoxia and ischemia: Reduced oxygen supply or blood flow to tissues.
Aging: Accumulation of damage and decline in cellular repair mechanisms.
The severity and consequences of cell injury depend on the type, duration, and intensity of the stressor, as well as the cell's ability to adapt or recover.