What do central chemoreceptors primarily respond to?

Central chemoreceptors are specialized neurons located primarily in the medulla oblongata of the brainstem. Their primary function is to monitor the composition of the cerebrospinal fluid (CSF) and respond predominantly to changes in the concentration of hydrogen ions (H+) and, indirectly, carbon dioxide (CO2) levels in the blood.

When carbon dioxide levels rise in the blood, it diffuses across the blood-brain barrier into the CSF, where it combines with water to form carbonic acid. This leads to a decrease in pH (an increase in H+ concentration). Central chemoreceptors detect this change, which signals the respiratory centers to increase the rate and depth of breathing in order to expel CO2 and restore normal pH levels. This response is crucial in maintaining homeostasis and ensuring proper acid-base balance in the body.

While blood pressure, oxygen levels, and body temperature are important physiological parameters, they are not the primary triggers for the activity of central chemoreceptors. Instead, peripheral chemoreceptors, found in the carotid bodies and aortic arch, are more responsive to changes in blood oxygen levels and blood pressure, making it essential to distinguish the specific roles of these different receptor types in the body’s respiratory