Practice question

Epimorphosis is regeneration type defined by formation of blastema mass through dedifferentiation of mature cells or mobilization of reserve progenitors forming proliferative growth zone that reconstructs lost structure. Unlike morphallaxis where existing tissue repatterned with minimal growth, epimorphosis involves extensive proliferation, histolysis of stump matrix, wound epidermis specialization. Examples include salamander limbs, zebrafish fins, lizard tails, requiring nerve trophic factors, FGF signaling, matrix metalloproteinases. Blastema later undergoes patterning and redifferentiation, restoring original architecture, thus representing growth-driven regeneration rather than remodeling or compensatory hypertrophy.