Healing

Medicine includes the process by which the cells in the body regenerate and repair to reduce the size of a damaged or necrotic area and replace it with new living tissue.

[3] In psychiatry and psychology, healing is the process by which neuroses and psychoses are resolved to the degree that the client is able to lead a normal or fulfilling existence without being overwhelmed by psychopathological phenomena.

[citation needed] Acute tubular necrosis (ATN) in the kidney is a case in which cells heal completely by regeneration.

[citation needed] The existing epithelial cells can replicate, and, using the basement membrane as a guide, eventually bring the kidney back to normal.

Also, damage to the collagen network (e.g. by enzymes or physical destruction), or its total collapse (as can happen in an infarct) cause healing to take place by repair.

Healing of a wound begins with clot formation to stop bleeding and to reduce infection by bacteria, viruses and fungi.

Fibroblasts quickly produce abundant type III collagen, which fills the defect left by an open wound.

Some of the fibroblasts mature into myofibroblasts which contain the same type of actin found in smooth muscle, which enables them to contract and reduce the size of the wound.

[citation needed] After inflammation has damaged tissue (when combatting bacterial infection for example) and pro-inflammatory eicosanoids have completed their function, healing proceeds in 4 phases.

[citation needed] In the Resolution phase, pathogens and damaged tissue are removed by macrophages (white blood cells).