internal oblique muscle

• internal oblique (ellipsis)

internal oblique muscle (plural internal oblique muscles)

1. (anatomy) A flat muscle situated under the external oblique muscle in the lateral and ventral part of the abdominal wall, that have aponeuroses extending medially to ensheathe the rectus muscles and fusing in the midventral line in the linea alba, and that act to compress the abdominal contents and to assist in expelling the contents of various visceral organs (as in urination, defecation, parturition, and expiration).

   Synonyms: obliquus internus, obliquus internus abdominis

   Coordinate term: external oblique muscle

• “oblique, .”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.