Final answer:
Central chemoreceptors in the medulla oblongata are sensitive to changes in pH due to the amount of carbon dioxide in the cerebrospinal fluid, which affects hydrogen ion concentration and triggers adjustments in the rate and depth of breathing.
Step-by-step explanation:
Central chemoreceptors are sensitive to pH in cerebrospinal fluid due to changes in the amount of carbon dioxide (CO2). As CO2 levels increase in the blood, it diffuses into the cerebrospinal fluid (CSF) where it forms carbonic acid, which dissociates into bicarbonate ions and hydrogen ions (H+), leading to a decrease in pH. Central chemoreceptors located in the medulla oblongata detect the rise in hydrogen ion concentration, signaling the respiratory centers to increase the rate and depth of breathing. This physiological response helps expel more CO2 from the lungs, reducing hydrogen ion concentration and thus bringing the pH back to normal levels.