Corpus: Anterior intercostal arteries

The anterior intercostal arteries are small branches of the internal thoracic artery in the intercostal space.

The anterior intercostal arteries supply the upper five or six intercostal spaces, with two vessels in each section. One vessel is located on the lower edge of the upper rib, another on the upper edge of the lower rib. They extend laterally and dorsally and anastomose with the posterior intercostal arteries. They are accompanied by the anterior intercostal veins.

They are first found between the parietal pleura and the internal intercostal muscles and then between the internal intercostal muscles and the external intercostal muscles.

The function of the anterior intercostal arteries is to supply the intercostal muscles. They supply the pectoral muscles and the mammary gland via branches that pierce the external intercostal muscles ("rami perforantes").