A 20 year old male was brought to the emergency depament after he suffered a stab wound in the anterior chest wall. CT scan revealed aerial extravasation from injury to the internal thoracic aery. The condition causes a decrease in blood supply through all of the following blood vessels, except
High-Yield Explanation
Posterior inntercostal aeries are not branches of the internal thoracic aery, hence there would be no decrease in blood supply through these aeries. There are 11 pairs of posterior intercostal aeries. The first 2 pairs are branches of superior intercostal aery, a branch of costocervical trunk. They are distributed to upper 2 intercostal spaces. The lower 9 pairs are branches of the descending thoracic aoa and are distributed to the lower 9 intercostal spaces. Branches of the internal thoracic aery: Terminal branches at the level of the 6th intercostal space: Superior epigastric aery. Musculophrenic aery. Sternal branches to: Transversus thoracis muscle Peritoneum of the posterior sternal surface. Sternal red bone marrow. Anterior intercostal aeries for the first 6 intercostal spaces. Perforating branches that pierce and supply pectoralis major and then become direct cutaneous vessels that supply the skin. Ref: Gray&;s Anatomy 41st edition Pgno: 942