The term “regeneration” is used to describe the sum total of activities leading to the regrowth of cells and tissues of the body. It includes both anatomical and physiological structures; however, structural regeneration does not necessarily lead to restoration of function. The term “functional regeneration” implies recovery of the function that can occur without regeneration by compensatory mechanisms. Regeneration follows damage or loss of cells and tissues that may be the result of trauma or pathological processes resulting in necrosis or apoptosis. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.