Answer:
1. Endoneurium covers the myelinated or unmyelinated axons. it is a layer of delicate connective tissue that envelops the myelin sheath of each of the myelinated nerve fiber.
2. Perineurium covers fascicles. It is the connective tissue sheath that envelops fascicle of nerve fibers within a nerve.
3. Epineurium covers nerves. It is the outermost layer of dense irregular connective tissue that envelops the peripheral nerve and multiple nerve fascicles.