Because of Their Smooth Muscle Content,_____________ are the Primary Determinants

Question

Because of their smooth muscle content,_____________ are the primary determinants of air flow.
A) trachea
B) bronchi
C) alveoli
D) bronchioles

Accepted Answer

The bronchioles, which are small branches of the bronchi, are the primary determinants of air flow due to their smooth muscle content. This smooth muscle allows for constriction and dilation of the bronchioles, which can greatly affect the amount of air that is able to pass through them. The trachea and bronchi also have smooth muscle, but to a lesser extent compared to the bronchioles. The alveoli, on the other hand, are responsible for gas exchange and do not have smooth muscle.