Which statement correctly describes the three parts of a muscle (origin, belly, insertion)?

• A. Insertion: portion of muscle joined to movable attachments; Belly: midsection; Origin: attached to bones or fixed muscles.
• B. Insertion: fixed; Belly: origin; Origin: movable attachments.
• C. Insertion: origin; Belly: insertion; Origin: belly.
• D. Insertion: muscle belly; Belly: insertion; Origin: belly and origin.

Answer: (A)

Understanding how a muscle is organized helps you remember what each term means: the origin is the fixed attachment, the belly is the thick, central portion, and the insertion is the movable attachment. When a muscle contracts, the part attached to the bone or structure at the insertion moves toward the origin, shortening the belly in the process.

The correct statement aligns with this: the insertion is the portion of the muscle joined to movable attachments; the belly is the midsection; and the origin is the attachment to bones or fixed structures. The other options mix up these roles or swap the terms, which isn’t how muscle anatomy is defined.