Which type of chemoreceptors are located in the medulla and respond to changes in the CNS?

Central chemoreceptors, which are located in the medulla oblongata of the brain, play a critical role in monitoring the chemical composition of the cerebrospinal fluid (CSF). They primarily respond to changes in the pH of the CSF, which reflects the levels of carbon dioxide (CO2) in the blood. When CO2 levels rise, it leads to an increase in hydrogen ions, resulting in a drop in pH. This change is detected by central chemoreceptors, which then stimulate the respiratory centers to increase ventilation to help eliminate excess CO2 from the body.

This mechanism is vital for maintaining homeostasis within the body, as it directly affects breathing rate and depth to ensure that oxygen levels remain sufficient while carbon dioxide is properly expelled. In contrast, the other types of receptors mentioned do not perform this specific function related to monitoring changes within the central nervous system. Peripheral chemoreceptors, for instance, are found in the carotid and aortic bodies and respond primarily to changes in blood oxygen levels rather than central changes in the CSF. Olfactory receptors are involved in the sense of smell and thermoreceptors detect changes in temperature, neither of which relate to the medulla’s response to chemical changes in the CNS.