Muscle satellite cells are Pax7+ cells derived from Pax3+/Pax7+ muscle progenitor cells of the central dermomyotome and are responsible for postnatal muscle growth, regeneration and maintenance of adult skeletal muscle. Satellite cells have a high nucleus-to-cytoplasm ratio. They are enclosed within their own membrane compartment, situated between the myofiber sarcolemma and the surrounding basal lamina of the myofiber. Muscle satellite cells in adult are mostly quiescent and are activated to proliferate and differentiate upon muscle injury or due to hypertrophic response mechanisms.