In which direction do oblique muscle fibers run?

• A. Parallel to the midline
• B. At an angle to the midline
• C. Circular around an opening
• D. Perpendicular to the midline

Answer: (B)

Verified step by step guidance

1. Understand the terminology: Muscle fibers are categorized based on their orientation relative to the midline of the body. The midline is an imaginary vertical line dividing the body into left and right halves.
2. Review the options: Parallel to the midline means the fibers run in the same direction as the midline. Perpendicular to the midline means the fibers run at a 90-degree angle to the midline. Circular around an opening refers to fibers forming a ring-like structure around an anatomical opening. At an angle to the midline means the fibers run diagonally relative to the midline.
3. Focus on the term 'oblique': In anatomy, 'oblique' refers to something that is slanted or angled rather than straight. This indicates that oblique muscle fibers do not run parallel or perpendicular to the midline but rather at an angle.
4. Apply anatomical examples: Oblique muscles, such as the external oblique and internal oblique muscles in the abdomen, are named for their angled fiber orientation relative to the midline of the body.
5. Conclude the direction: Based on the definition and examples, oblique muscle fibers run at an angle to the midline, distinguishing them from other orientations like parallel, perpendicular, or circular.