Pulmonary arteriole (magnified)
Arteriola pulmonalis
RespiratoryOrgansWhole bodyRight side
- What it is
- Branch of the pulmonary artery that runs beside the bronchiole and divides with it to feed the alveolar capillaries; shown blue because it carries deoxygenated blood.
- Function
- Delivers blood from the right ventricle to the gas-exchange surface.
- Size
- Real pulmonary arterioles are ~15–100 µm in diameter.
- Clinical note
- Unlike systemic arterioles, pulmonary arterioles constrict when alveolar oxygen is low (hypoxic vasoconstriction), diverting blood to well-ventilated lung.