Central chemoreceptors, which regulate breathing, are located in which part of the brain?

• A. Pons
• B. Cerebellum
• C. Cortex
• D. Medulla

Answer: (D)

Central chemoreceptors that regulate breathing are located in the medulla oblongata, a part of the brainstem. They sit on the ventral surface near the fourth ventricle and monitor the chemical environment of the cerebrospinal fluid. CO2 easily crosses into CSF and forms carbonic acid, which dissociates to hydrogen ions; the central chemoreceptors detect these pH changes and drive adjustments in ventilation via the brain’s respiratory centers to keep CO2 levels in balance.

The pons helps fine-tune breathing patterns but does not house these central detectors. The cortex can influence breathing voluntarily, yet it does not contain the CO2-sensing chemoreceptors. The cerebellum coordinates movement and balance, not the chemical control of respiration.