Final answer:
The low partial pressure of CO2 in the alveolus prompts the bronchioles to dilate, resulting in increased airflow; the correct answer is a) Dilate, increase.
Step-by-step explanation:
When there is dead space in the alveolus, resulting in a low partial pressure of CO2, the body responds by changing the diameter of the bronchioles.
This is a part of the body's mechanism to regulate ventilation and ensure efficient gas exchange. The correct answer to the question is a) Dilate, increase.
A lower than normal partial pressure of CO2 in the alveoli triggers the bronchioles to dilate (increase in diameter), which in turn increases air flow into and out of the lungs.
This response aligns with the fact that ventilation is regulated by the diameter of the airways, and the smooth muscles in the bronchioles respond accordingly to the levels of CO2.
An increased diameter of the airways means less resistance to airflow, facilitating the exhalation of carbon dioxide and the inhalation of oxygen.
The correct answer to the question is a) Dilate, increase.