Which gas is primarily responsible for the regulation of respiratory drive?

The regulation of respiratory drive is primarily influenced by the levels of carbon dioxide in the blood. This is due to the role of carbon dioxide as an indicator of metabolic activity. When carbon dioxide levels rise, it leads to an increase in the acidity of the blood, which is sensed by chemoreceptors located in the brain and in the arteries. These receptors respond to elevated carbon dioxide levels by signaling the respiratory center to increase the rate and depth of breathing. This mechanism ensures that excess carbon dioxide is expelled from the body, thus maintaining acid-base balance and ensuring sufficient oxygen delivery. The body prioritizes the regulation of carbon dioxide over oxygen because maintaining proper carbon dioxide levels is critical for essential physiological functions.