Internal Mammary Artery - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The internal mammary artery (internal thoracic artery) is an artery of the anterior chest wall. It supplies the skin and muscles of the anterior thoracic cage, the breast, and the superior aspect of the abdominal wall. 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 Course The internal mammary artery arises from the proximal portion of the subclavian artery. It then travels inferiorly along the inner surface of the anterior chest wall – approximately 2cm lateral to the sternal margin. The vessel descends in a neurovascular plane between the internal intercostal muscles and costal cartilages anteriorly, and the transversus thoracis muscle posteriorly. Along its course, the internal mammary artery gives rise to several branches: Anterior intercostal arteries Pericardiophrenic artery Perforating cutaneous branches Once the internal mammary artery reaches the 6th to 7th costal cartilage, it bifurcates into its terminal branches – superior epigastric artery and musculophrenic artery. By TeachMeSeries Ltd (2026) Fig 1Anatomical course of the internal mammary artery. Supply The internal mammary artery contributes to the blood supply of the following structures: Anterior thoracic wall (sternum, ribs, costal cartilage and intercostal muscles) Pectoral muscles, subcutaneous tissue and skin over the anterior chest Breasts Via the pericardiophrenic artery – thymus, phrenic nerves, pericardium and diaphragm By TeachMeSeries Ltd (2026) Fig 2The internal mammary artery contributes to the blood supply of the structures of the anterior chest wall. Frequent questions What is the internal mammary artery? The internal mammary artery, also known as the internal thoracic artery, is a major vessel supplying the anterior chest wall, including the skin, muscles, and breasts. It originates from the subclavian artery and runs along the inner surface of the chest wall. What structures are supplied by the internal mammary artery? The internal mammary artery supplies the anterior thoracic wall, pectoral muscles, skin over the chest, and the breasts. Additionally, it provides blood to the thymus, phrenic nerves, pericardium, and diaphragm through its branches. Where does the internal mammary artery originate? The internal mammary artery arises from the proximal part of the subclavian artery. It then descends along the anterior chest wall, positioned about 2cm lateral to the sternum. What branches does the internal mammary artery give rise to? The internal mammary artery gives rise to several branches, including the anterior intercostal arteries, the pericardiophrenic artery, and perforating cutaneous branches. These branches play a crucial role in supplying various thoracic structures. What is the course of the internal mammary artery? The internal mammary artery travels inferiorly along the inner surface of the anterior chest wall, situated between the internal intercostal muscles and costal cartilages anteriorly, and the transversus thoracis muscle posteriorly. It bifurcates into the superior epigastric artery and musculophrenic artery at the 6th to 7th costal cartilage. Rate This Article