rectus abdominis /rek″təs/ , one of a pair of anterolateral muscles of the abdomen, extending the whole length of the ventral aspect of the abdomen. The pair is separated by the linea alba. Each rectus arises in a lateral tendon from the crest of the pubis and is interlaced by a medial tendon with the muscle of the opposite side. The rectus abdominis inserts into the fifth, sixth, and seventh ribs. It functions to flex the vertebral column, tense the anterior abdominal wall, and assist in compressing the abdominal contents. Compare external abdominal oblique muscle, internal abdominal oblique muscle, pyramidalis, transversus abdominis.
