Innervation of the Abdominal Wall The anterior rami of spinal nerves T7-L1 innervate the anterolateral abdominal wall. The anterior divisions of the intercostal nerves (T7-11) enter the abdominal wall between the internal oblique and transversus abdominis muscles; they continue in this space anteriorly until they pierce and innervate the rectus abdominis and end as anterior […]