Which term refers to the narrowing of the airways due to tightening of surrounding smooth muscle?

Which term refers to the narrowing of the airways due to tightening of surrounding smooth muscle?

• A. Bronchodilation
• B. Chemoreceptors
• C. Alpha 1 receptors
• D. Bronchoconstriction

Answer: (D)

Airway narrowing from tightening of smooth muscle around the airways reduces the radius and raises resistance to airflow. This tightening is called bronchoconstriction. It contrasts with bronchodilation, where the smooth muscle relaxes and the airways widen to allow more air through. Chemoreceptors are sensors that detect chemical changes and help regulate breathing, but they don’t cause the airways to constrict themselves. Alpha-1 receptors are mainly involved in constricting blood vessels, not the smooth muscle of the airways. Bronchodilation describes the widening of the airways, not the narrowing.

Airway narrowing from tightening of smooth muscle around the airways reduces the radius and raises resistance to airflow. This tightening is called bronchoconstriction. It contrasts with bronchodilation, where the smooth muscle relaxes and the airways widen to allow more air through. Chemoreceptors are sensors that detect chemical changes and help regulate breathing, but they don’t cause the airways to constrict themselves. Alpha-1 receptors are mainly involved in constricting blood vessels, not the smooth muscle of the airways. Bronchodilation describes the widening of the airways, not the narrowing.