Transversus Thoracis - Podcast Version TeachMeAnatomy 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The transversus thoracis is a muscle of the thoracic wall. It is located on the internal surface of the thoracic wall and is continuous with the transversus abdominis inferiorly. Attachments: Arises from the posterior surface of the inferior sternum and costal cartilage of the lower ribs. The fibres ascend and attach onto the internal surface of costal cartilages 2-6. Actions: Weak depressor of the ribs during expiration. Innervation: Intercostal nerves (T2-T6). Blood supply: Internal thoracic artery. By TeachMeSeries Ltd (2025) Fig 1View of the internal aspect of the thoracic wall. The internal intercostal and transverse thoracis muscles are visible. 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 Rate This Article