Final answer:
During hypoventilation, PO2 levels decrease and PCO2 levels increase.
Step-by-step explanation:
During hypoventilation, PO2 levels decrease and PCO2 levels increase.
When we hypoventilate, it means we are breathing at a slower rate or taking shallow breaths. This leads to less oxygen entering the lungs and less carbon dioxide being removed. As a result, the levels of oxygen in the blood, represented by PO2, decrease. Conversely, the levels of carbon dioxide in the blood, represented by PCO2, increase.