What term describes a bundle of muscle fibers within a skeletal muscle?

• A. Epimysium
• B. Fascicle
• C. Endomysium
• D. Myofibril

Answer: (B)

The main idea here is how skeletal muscle is organized into nested bundles. A bundle of muscle fibers within a skeletal muscle is called a fascicle. Each fascicle is a group of muscle fibers wrapped in a connective tissue sheath called the perimysium. The whole muscle is wrapped by the epimysium, while each individual fiber inside a fascicle is wrapped in its own connective tissue layer, the endomysium. Inside each muscle fiber are the myofibrils, the contractile elements.

So, fascicle is the term for a bundle of muscle fibers, distinguishing it from the surrounding tissue layers (epimysium around the whole muscle and endomysium around each fiber) and from the contractile subunits inside the fibers (myofibrils).