Supportive cartilage disappears from the bronchial tree at the level of the
A) alveolar duct.
B) bronchioles.
C) lobar bronchi.
D) respiratory bronchiole.

Question

Quizplus · Accepted Answer

Supportive cartilage disappears from the bronchial tree at the level of the bronchioles. Beyond this point, the air passages are lined with smooth muscle, which allows them to constrict and dilate in response to various stimuli.

Supportive Cartilage Disappears from the Bronchial Tree at the Level