Which term describes the membrane that encloses a muscle fiber?

Which term describes the membrane that encloses a muscle fiber?

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

Answer: (C)

The main idea is the specialized cell membrane that surrounds a muscle fiber—the sarcolemma. This is the plasma membrane of the muscle cell, enclosing the cytoplasm (sarcoplasm) and serving as the site where electrical signals travel into the fiber to initiate contraction, often via its connections with T-tubules that help trigger calcium release. Endomysium, perimysium, and epimysium are connective tissue wrappers at different levels of organization: endomysium surrounds each individual muscle fiber, perimysium groups fibers into fascicles, and epimysium encases the whole muscle. So the membrane that encloses a single muscle fiber is the sarcolemma.

The main idea is the specialized cell membrane that surrounds a muscle fiber—the sarcolemma. This is the plasma membrane of the muscle cell, enclosing the cytoplasm (sarcoplasm) and serving as the site where electrical signals travel into the fiber to initiate contraction, often via its connections with T-tubules that help trigger calcium release.

Endomysium, perimysium, and epimysium are connective tissue wrappers at different levels of organization: endomysium surrounds each individual muscle fiber, perimysium groups fibers into fascicles, and epimysium encases the whole muscle. So the membrane that encloses a single muscle fiber is the sarcolemma.