Which is the most proximal part of the air distribution system that no longer contains cartilage?
A) Primary bronchi
B) Secondary bronchi
C) Bronchioles
D) Alveolar ducts

Question

Quizplus · Accepted Answer

Cartilage is present in the walls of the trachea and larger bronchi, but as the airways branch into smaller bronchioles, the cartilage disappears. Therefore, the most proximal part of the air distribution system that no longer contains cartilage is the bronchioles. The primary and secondary bronchi still contain cartilage. Alveolar ducts are not technically part of the air distribution system as they are the terminal end of the respiratory tree where gas exchange occurs.

Which Is the Most Proximal Part of the Air Distribution