Physiology Concerning the central chemoreceptors, True is: A They are located near the dorsal surface of the medulla B They respond to both the PCO2 and the PO2 of the blood C They are activated by changes in the pH of the surrounding extracellular fluid D For a given rise in PCO2, the pH of cerebrospinal fluid falls less than that of blood 💡 Explanation Concerning the central chemoreceptors, True is: ✓ Correct Answer: C. They are activated by changes in the pH of the surrounding extracellular fluid