What is the role of secondary bronchi in the respiratory system?

• A. House passageways smaller than primary bronchi
• B. Passageway for air
• C. Contain alveolar sacs
• D. Facilitate gas exchange with blood

Answer: (B)

The primary role of the secondary bronchi in the respiratory system is to serve as a passageway for air entering the lungs. After air passes through the trachea and divides into the primary bronchi, which lead to each lung, it continues into the secondary bronchi. These bronchi further branch into smaller tertiary bronchi, effectively transporting air deeper into the lungs.

While other components of the respiratory system are involved in gas exchange and the housing of smaller passageways or structures like alveolar sacs, the primary function of secondary bronchi centers on directing airflow within the lungs. Their structure allows them to effectively channel air further into the intricately divided airway system, ensuring that oxygen reaches the alveoli where actual gas exchange occurs.