Which structure primarily maintains the respiratory drive?

The structure primarily responsible for maintaining the respiratory drive is the peripheral chemoreceptors. These receptors are sensitive to changes in arterial blood gas levels, particularly oxygen (O2), carbon dioxide (CO2), and pH. Peripheral chemoreceptors, located in the carotid and aortic bodies, detect low oxygen levels and elevated carbon dioxide levels, triggering an increase in the rate and depth of respiration. This response ensures sufficient oxygen is delivered to the tissues while facilitating the removal of carbon dioxide.

The cerebral cortex does play a role in the voluntary control of breathing, but it is not the primary regulator of the automatic respiratory drive. The alveoli are involved in the gas exchange process but do not directly influence the respiratory rate. The lungs facilitate the passage of air and the exchange of gases but, like the alveoli, do not function as regulators of the respiratory drive. Thus, the peripheral chemoreceptors are crucial for maintaining homeostasis related to breathing and gas exchange.