Which statement about how skeletal muscles are named is true?

Which statement about how skeletal muscles are named is true?

• A. Direction of muscle fibers is a criterion.
• B. Color of the muscle is a criterion.
• C. Length of the muscle is a criterion.
• D. Time of day the muscle is used is a criterion.

Answer: (A)

Muscle names often tell you how the fibers run, so the direction of muscle fibers is a reliable and widely used criterion. Terms like rectus, obliquus, and transversus describe straight, diagonal, or horizontal fiber orientations, which also indicate how the muscle pulls on a bone. For example, rectus muscles have fibers that run parallel to the body's long axis, suggesting a straight pull, while oblique muscles have angled fibers that produce a different pull direction. Color isn’t used in naming, and time of day has no anatomical basis. Length appears in some names (like longus or brevis) but isn’t as universally informative as fiber direction for understanding how a muscle functions.

Muscle names often tell you how the fibers run, so the direction of muscle fibers is a reliable and widely used criterion. Terms like rectus, obliquus, and transversus describe straight, diagonal, or horizontal fiber orientations, which also indicate how the muscle pulls on a bone. For example, rectus muscles have fibers that run parallel to the body's long axis, suggesting a straight pull, while oblique muscles have angled fibers that produce a different pull direction. Color isn’t used in naming, and time of day has no anatomical basis. Length appears in some names (like longus or brevis) but isn’t as universally informative as fiber direction for understanding how a muscle functions.