What determines the airway diameter in the normal lung?
A) Balance between sympathetic and parasympathetic tone
B) In large part, the amount of patient effort
C) Activity level of the submucosal glands
D) Amount of dopamine present in the airway walls

Question

Quizplus · Accepted Answer

Both sympathetic and parasympathetic postganglionic efferents innervate the smooth muscle and glands of the airways. They influence the diameter of the airway by causing more or less tension in the smooth muscles that wrap the airway and influence glandular secretion. The combined effects of the parasympathetic and sympathetic nervous activity, which generally oppose each other's action, result in a balanced control of airway diameter.

What Determines the Airway Diameter in the Normal Lung