From which source do bronchial arteries originate, and what do they supply?

• A. From systemic circulation (usually from the aorta); supply conducting airways with oxygenated blood.
• B. From pulmonary arteries; supply the alveoli with deoxygenated blood.
• C. From internal thoracic arteries; supply visceral pleura with blood.
• D. From bronchial veins; drain the alveolar capillaries.

Answer: (A)

Bronchial arteries are part of the systemic circulation, not the lung’s gas‑exchange system. They typically arise from the thoracic aorta (sometimes from nearby intercostal arteries) and deliver oxygenated blood to the walls of the trachea and bronchi and to the visceral pleura, nourishing the conducting airways. They do not supply the alveoli or their capillaries—that job belongs to the pulmonary arteries, which carry deoxygenated blood from the heart for gas exchange and drain into the pulmonary veins after oxygenation. In short, bronchial arteries come from the aorta and feed the conducting airways with oxygenated blood, while the alveoli are served by the pulmonary circulation.