Question

 Incomplete cartilaginous rings extend from trachea to

Primary bronchi

Secondary bronchi

Initial bronchioles

Terminal bronchioles
​

Answer 1

Answer:

The tracheae, primary, secondary and tertiary bronchi and initial bronchioles are supported by incomplete cartilaginous rings, which prevents them from collapsing. Each terminal bronchiole gives rise to a number of very thin, irregular walled and vascularised bag-like structures called as alveoli.

Explanation: