Feedback Loops and Homeostatic Regulation (3A) Practice Test

A patient with chronic obstructive pulmonary disease has baseline arterial $P_{CO_2}$ of 55 mmHg with near-normal pH due to renal compensation. When given a high-flow oxygen mask, ventilation decreases and $P_{CO_2}$ rises further. Based on the scenario, which outcome aligns with the feedback loop controlling ventilation in this patient?

A patient is given a short-acting beta-agonist for acute bronchospasm. Within minutes, airway resistance decreases and ventilation improves, lowering arterial $P_{CO_2}$ from 48 to 40 mmHg. The patient’s respiratory rate decreases slightly afterward. Based on the scenario, which outcome aligns with the feedback loop controlling arterial $P_{CO_2}$?