it is Adaptations i think
The layer of connective tissue, called the _perimysium_ , extends inward from the epimysium and separates the muscle tissue into small sections. these sections contain bundles of skeletal muscle fibers called _fascicles_ .
Additionally, bundles of contractile proteins called fibrils fill a muscle cell, called a fiber. Outside of each fiber, is the connective tissue endomysium. Bundles of fibers form fascicles, surrounded by perimysium. Bundles of fascicles and perimysium comprise the entire muscle organ, which is enclosed by epimysium.
