Final answer:
It is false that oxygen levels are the most important stimuli for breathing; rather, carbon dioxide levels play a more significant role in regulating respiration in a healthy individual.
Step-by-step explanation:
It is false that changes in oxygen levels in the blood are the most important stimuli for breathing in a healthy person. While peripheral chemoreceptors in the aortic arch and carotid arteries do respond to significant drops in blood oxygen levels (below approximately 60 mm Hg) by increasing respiratory activity, it is actually the levels of carbon dioxide that are most closely monitored to maintain blood gas homeostasis.
The central chemoreceptors in the brain sense changes in CO2 levels, as well as the pH of the blood, and adjust the respiratory rate accordingly. A rise in carbon dioxide levels or a drop in oxygen levels will trigger an increase in respiratory rate and depth through the actions of the respiratory centers in the brain. However, carbon dioxide's influence is a more powerful respiratory stimulant than oxygen under normal conditions.