GO:0014719

A change in the morphology or behavior of a satellite cell resulting from exposure to an activating factor such as a cellular or soluble ligand. Satellite cells are quiescent cells that are located between the basal lamina and the plasmalemma of the muscle fiber, which are the main contributors to postnatal muscle growth. In adult muscle, satellite cells become activated to divide and differentiate in response to muscle damage. [GOC:mtg_muscle]