Final answer:
Bronchioles and systemic arterioles either dilate or constrict in response to imbalances in ventilation and perfusion to optimize gas exchange. If ventilation is greater than perfusion, arterioles dilate and bronchioles constrict; if perfusion is greater, bronchioles dilate and arterioles constrict.
Step-by-step explanation:
The response to what happens to bronchioles and systemic arterioles is related to how the body compensates for mismatches in ventilation and perfusion in the lungs. If ventilation is greater than perfusion, the systemic arterioles dilate and the bronchioles constrict, which increases perfusion to match ventilation. Conversely, if ventilation is less than perfusion, the bronchioles dilate and the systemic arterioles constrict. This physiological response helps to optimize the exchange of oxygen and carbon dioxide in the lungs.