The transversus abdominis is a muscle of the anterior abdominal wall. It is the deepest of the flat abdominal wall muscles. Attachments: Originates from the inguinal ligament, costal cartilages 7-12, the iliac crest and thoracolumbar fascia. It inserts onto the conjoint tendon, xiphoid process, linea alba and the pubic crest. Actions: Compression of abdominal contents. Innervation: Thoracoabdominal nerves (T7-T11), subcostal nerve (T12) and branches of the lumbar plexus. Blood supply: Lower posterior intercostal and subcostal arteries, superior and inferior epigastric arteries, superficial and deep circumflex arteries, posterior lumbar arteries. By OpenStax [CC BY 4.0], via Wikimedia Commons Fig 1The muscles of the anterolateral abdominal wall. Note how the flat muscles form aponeuroses medially. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Pro Feature - Dissection Images Dissection of the inferior epigastric artery arising from the external iliac artery. It then ascends on the posterior surface of the rectus abdominis. Dissection of the inferior epigastric artery arising from the external iliac artery. It then ascends on the posterior surface of the rectus abdominis. You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More Print Article Rate This Article