Which abdominal muscle runs vertically from the rib cage to the pubic crest?

Which abdominal muscle runs vertically from the rib cage to the pubic crest?

• A. Rectus abdominis
• B. External oblique
• C. Internal oblique
• D. Transversus abdominis

Answer: (A)

Understanding how fiber direction and attachments define abdominal muscles helps identify which runs straight up and down. The rectus abdominis is a long vertical strap that travels along the front of the abdomen from the pubic crest and pubic symphysis up to the xiphoid process and the lower ribs, giving it a vertical orientation. That vertical path is what the question is describing. The other muscles have different fiber directions: the external oblique fibers run diagonally downward from the ribs toward the midline and pelvis, the internal oblique fibers run diagonally upward, and the transversus abdominis fibers run horizontally across the abdomen. The rectus abdominis also contributes to bending the trunk forward and increasing intra-abdominal pressure.

Understanding how fiber direction and attachments define abdominal muscles helps identify which runs straight up and down. The rectus abdominis is a long vertical strap that travels along the front of the abdomen from the pubic crest and pubic symphysis up to the xiphoid process and the lower ribs, giving it a vertical orientation. That vertical path is what the question is describing. The other muscles have different fiber directions: the external oblique fibers run diagonally downward from the ribs toward the midline and pelvis, the internal oblique fibers run diagonally upward, and the transversus abdominis fibers run horizontally across the abdomen. The rectus abdominis also contributes to bending the trunk forward and increasing intra-abdominal pressure.