Which layer directly surrounds an individual skeletal muscle fiber?

• A. Epimysium
• B. Fascia
• C. Endomysium
• D. Perimysium

Answer: (C)

Directly surrounding each skeletal muscle fiber is the endomysium. This thin sleeve of connective tissue wraps every individual muscle cell, keeping neighboring fibers separate and providing a microenvironment with tiny blood vessels and nerve endings that serve that fiber—and housing satellite cells for repair. This focused placement is what distinguishes it from the other layers: the epimysium surrounds the entire muscle, the perimysium encases a fascicle (a bundle of fibers), and the fascia is a broader connective tissue sheet that envelopes muscles or groups of muscles. Understanding this hierarchy shows why the endomysium is the layer that directly interfaces with a single muscle fiber.