ABSTRACT
The most common cause in clinical practice is hypoxia, where the cell is damaged because aerobic respiration is diminished. Hypoxia can occur when there is a reduction in the blood supply to a tissue, as occurs in myocardial infarction. Apoptosis may be a physiological phenomenon, playing a key role in the programmed remodelling of tissues during embryogenesis and in the shaping of the immune system with the programmed deletion of autoreactive T cells. The relative roles of regeneration and the connective tissue response vary in different tissues. In some tissues, e.g. skin, there may be a complete restoration of the epithelial architecture after healing, particularly if the injury is very superficial. The dermis and subcutaneous tissues are repaired by the formation of small amounts of granulation tissue. The term ‘contracture’ is used when the repair process ultimately leads to distortion or limitation of movement of the tissues.
