Satelliitrakud

Satelliitrakud, also known as satellite cells, are a population of quiescent myogenic stem cells located in close proximity to skeletal muscle fibers. They reside in a niche between the sarcolemma and the basal lamina. Under normal physiological conditions, these cells are largely dormant. However, upon muscle injury or during periods of increased demand such as growth or hypertrophy, satellite cells become activated.

Activation triggers a series of events including proliferation and differentiation. Proliferating satellite cells, now called myoblasts, can then fuse with existing muscle fibers to repair damage and increase fiber size, or they can fuse with each other to form new muscle fibers. This process of regeneration and repair is crucial for maintaining muscle mass and function throughout life. The precise mechanisms regulating satellite cell activation, proliferation, and differentiation are complex and involve a variety of signaling pathways and factors. Their ability to self-renew ensures a continuous supply of myogenic precursors. Satellite cells are considered the primary mediators of skeletal muscle regeneration.