Which connective tissue layer surrounds a single muscle fiber?

Which connective tissue layer surrounds a single muscle fiber?

• A. Endomysium
• B. Epimysium
• C. Perimysium
• D. Nerve fascicle

Answer: (A)

Muscle organization at the smallest scale includes a thin connective tissue sleeve around each individual fiber. This sleeve, the endomysium, sits between the sarcolemma of one fiber and its neighbors, creating a tiny environment that supplies the fiber with capillaries and nerve endings and houses satellite cells for repair. That specialized microenvironment is what makes endomysium the correct layer surrounding a single muscle fiber. To place it in the bigger picture: the epimysium wraps the whole muscle, the perimysium bundles many fibers into fascicles, and a nerve fascicle is a bundle of nerve fibers, not a layer around a muscle fiber.

Muscle organization at the smallest scale includes a thin connective tissue sleeve around each individual fiber. This sleeve, the endomysium, sits between the sarcolemma of one fiber and its neighbors, creating a tiny environment that supplies the fiber with capillaries and nerve endings and houses satellite cells for repair. That specialized microenvironment is what makes endomysium the correct layer surrounding a single muscle fiber.

To place it in the bigger picture: the epimysium wraps the whole muscle, the perimysium bundles many fibers into fascicles, and a nerve fascicle is a bundle of nerve fibers, not a layer around a muscle fiber.