perimysium perimysium perimysium is a sheath of connective tissue that groups muscle fibers into bundles (anywhere between 10 and 100 or more) or fascicles. perimysiumstructure of a skeletal muscle. (perimysium labeled at top center.)detailsidentifierslatinperimysiumta98a04.0.00.042ta22008thh3.03.00.0.00005 fma9728anatomical terminology studies of muscle physiology suggest that the perimysium plays a role in transmitting lateral contractile movements. this hypothesis is strongly supported in one exhibition of the existence of "perimysial junctional plates" in ungulate flexor carpi radialis muscles constructed by emilie passerieux. the overall comprehensive organization of the perimysium collagen network, as well as its continuity and disparateness, however, have still not been observed and described thoroughly everywhere within the muscle. found to have type i, iii, vi, and xii collagen.