Arcuate line-the rectus sheath is a tough, tendinous sheath over the rectus abdominis muscle. it covers the entire anterior surface of the rectus abdominis. however, on the posterior side of the muscle, the sheath is incomplete- it ends inferiorly at the arcuate line. below the arcuate line, the rectus abdominis is covered by transversalis fascia, not the rectus sheath! The linea alba is also related to the rectus abdominis-it is a ligament that runs down the middle of the abdomen, bisecting the rectus abdominis. it is made by the intermingling of the aponeuroses of the external oblique, internal oblique, and transversus abdominis. its a good place to make a vertical incision. all of the other answer choices are related to the inguinal canal. the falx inguinalis (sometimes called the inguinal falx or conjoint tendon), is the inferomedial attachment of transversus abdominis with some fibers of internal abdominal oblique-it contributes to the posterior wall of the inguinal canal. the inguinal ligament is the ligament that connects the anterior superior iliac spine with the pubic tubercle-it makes the floor of the inguinal canal. the internal (deep) inguinal ring is the entrance to the inguinal canal, where the transversalis fascia pouches out and creates an opening through which structures can leave the abdominal cavity.