Figure 2.

Schematic of skeletal muscle healing. Day 2: Necrotic muscle tissue is removed by macrophages while fibroblasts form scar tissue in the central zone (CZ). Day 3: Satellite cells are activated within the basal lamina cylinders in the regeneration zone (RZ). Day 5: Myoblasts fuse into myotubes in the RZ and scar tissue in the CZ is now denser. Day 7: Regenerating muscle cells migrate into the CZ and begin to pierce through the scar. Day 14: The scar of the CZ is reduced in size, and the regenerating myofibers close the CZ gap. Day 21: The interlacing myofibers are virtually fused with little intervening connective tissue (scar) in between. Reprinted with permission from Järvinen et al.³⁵