A 18-year-old male with history cystic fibrosis. While attending a class, he suddenly begins to cough up large volumes of bright red blood. He was admitted to nearby hospital in emergency depament. With above clinical scenario which vessel is most likely to bleed?

Hemoptysis is a common feature in patients with bronchiectasis and cystic fibrosis due to chronic inflammation and anatomical abnormalities that bring the bronchial aeries closer to the mucosal surface. These blood vessels are present closer to air space, because of which even a smaller degree of inflammation in these areas can lead to rupture of vessels into the airway. Bronchial aeries are under systemic pressure; thus, they are prone to large amounts of bleeding.