Is breathing rate controlled by positive feedback?

No, breathing rate is primarily controlled by negative feedback mechanisms. The body monitors carbon dioxide levels in the blood, and when they rise, chemoreceptors signal the respiratory centers in the brain to increase the breathing rate, thereby expelling more CO2. This regulation maintains homeostasis, preventing excessive fluctuations in gas levels. Positive feedback is not a typical mechanism for controlling breathing, as it could lead to uncontrolled increases in respiration.