The middle part of a muscle is known as the ______.

• A. Origin
• B. Insertion
• C. Belly
• D. Tendon

Answer: (C)

The middle part of a muscle is called the belly. This is the fleshy, central region where the muscle fibers are most abundant and where contraction mainly occurs to generate force. The points where a muscle attaches to bone—the origin, typically the fixed anchor—and the insertion, the movable attachment—define the ends of the muscle, not the middle. A tendon is the connective tissue band that links muscle to bone, not the muscle’s midsection. So the term that describes the central, contracting part is the belly.