Which process results in decreased internal diameter of the airway?

Which process results in decreased internal diameter of the airway?

• A. Bronchodilation
• B. Hyperventilation
• C. Bronchoconstriction
• D. Hypoventilation

Answer: (C)

Bronchoconstriction is the process that results in the decreased internal diameter of the airway. This occurs when the smooth muscles surrounding the bronchi and bronchioles contract, which reduces airflow and increases resistance in the respiratory system. When the airways narrow, it becomes more difficult for air to move in and out of the lungs, potentially leading to symptoms such as wheezing or shortness of breath.

In contrast, bronchodilation works to increase the internal diameter of the airways, allowing for easier airflow. Hyperventilation and hypoventilation refer to changes in the rate and depth of breathing rather than the structural changes in airway diameter. Therefore, bronchoconstriction specifically highlights the physiological event that leads to constriction of the airways.