Final answer:
Tertiary bronchi supply specific regions within the lungs known as bronchopulmonary segments.
Step-by-step explanation:
Tertiary bronchi, also known as segmentalinic bronchi, supply specific regions within the lungs. Each bronchopulmonary segment, which is a division of a lobe in the lungs, receives air from its own tertiary bronchus. This ensures that each segment is supplied with air and blood from its own bronchus and artery, respectively.