Which of the following has maximum smooth muscle as compared to wall thickness?
High-Yield Explanation
Along the entire intrapulmonary bronchial tree, smooth muscle forms two opposed helical tracts, which become thinner and finally disappear at the level of the alveoli. Terminal bronchiole has the maximum smooth muscle among all the given options. Terminal bronchiole > Respiratory bronchiole >Alveolar ducts > Alveoli