Age changes in skeletal muscle cells, proliferation and glycogen

Skeletal muscle is a dynamic organ that is subjected to changes throughout the human life, starting from intrauterine life till old age period. Aging affect this organ in different aspects as vascularization, fiber typing, connective tissue contents, and ultimately affect the cellular and sub-cellular features. Aging affect the population of skeletal muscle resident cells specifically the satellite cells and myonuclei, which are responsible for fiber formation and maintenance respectively, the proliferation profile of satellite cells were declined with aging leaving only low mitotic activity in old age that's barley able to maintain myonuclear cells pool. Aging also affect the skeletal muscle metabolic activity as glucose transport and oxidation, this intern reflected on glycogen contents, that tend to accumulate in old age within the skeletal muscle fibers. All these changes together make skeletal muscle fibers atrophied, weaker and more prone to damage in old age group.