Fig. 1.

Three different adipose depots in skeletal muscle. (A) Skeletal muscle is made up of intramyocellular myofibrils, muscle fibers, and fascicles bound together by successively thicker connective tissue layers (i.e., endomysium, perimysium, and epimysium). (B) Skeletal muscle fat may be classified into intramyocellular (lipid droplets filling the cytoplasm between the myofibrils of elongated myocytes) and extramyocellular components. Adipocytes may infiltrate between muscle fibers (intramuscular fat) and fascicles (intermuscular fat) or exist around the epimysium as extramuscular fat depots of adipose tissue. Reprinted from Altajar et al. [5].