Question

multiple choice question
central chemoreceptors monitor the ______ of the brain.
o ph
o carbon dioxide levels
o oxygen levels

Explanation:

Central chemoreceptors are sensitive to changes in the pH of the cerebrospinal fluid (CSF), which is influenced by the partial pressure of carbon dioxide (\(P_{CO_2}\)) in the blood. When \(P_{CO_2}\) increases, it diffuses into the CSF and combines with water (\(H_2O\)) to form carbonic acid (\(H_2CO_3\)), which then dissociates into hydrogen ions (\(H^+\)) and bicarbonate ions (\(HCO_3^-\)). The increase in \(H^+\) lowers the pH of the CSF, and central chemoreceptors detect this pH change. While carbon dioxide levels indirectly affect the pH (as explained above) that the central chemoreceptors monitor, the direct parameter they sense is the pH. Oxygen levels are mainly monitored by peripheral chemoreceptors (like the carotid and aortic bodies), not central chemoreceptors.

Answer:

pH