Final answer:
Epi, peri, and endomysium are connective tissue coverings in muscular structure and are comparable to the connective tissue layers (endoneurium, perineurium, epineurium) found in the peripheral nervous system.
Step-by-step explanation:
Epi, peri, and endomysium have in common that they are all connective tissue coverings found in muscular structure. These connective tissues are analogous to the endoneurium, perineurium, and epineurium found in the peripheral nervous system (PNS), which are also connective tissue layers that protect and support nerve fibers. Specifically, endomysium surrounds individual muscle fibers, perimysium encloses bundles of muscle fibers called fascicles, and epimysium surrounds the entire muscle. Similarly, endoneurium wraps each individual nerve fiber, perineurium packs those fibers into bundles called fascicles, and epineurium is the outermost layer that encases the entire nerve. Therefore, the correct answer to what they all have in common is that they are all connective tissue coverings.