The connective tissue layer around each muscle fascicle

During embryogenesis, skeletal muscle develops through the fusion of mononucleated precursor cells (myoblasts) into multinucleated myotubes. These subsequently mature into myofibers (muscle fibers) of varying length that contain thousands of nuclei. In adult tissues, these myofibers are arranged in fascicles, each associated with a small pool of tissue stem cells referred to as satellite cells, which can contribute to muscle regeneration following injury. Perimysium is the sheath of connective tissue surrounding a bundle of muscle fibers .Ref: Guyton; 13th edition