What type of receptors are primarily responsible for detecting changes in carbon dioxide levels in the blood?

Peripheral chemoreceptors are primarily responsible for detecting changes in carbon dioxide levels in the blood. These receptors are located in specific areas outside the central nervous system, particularly in the carotid arteries and the aortic arch. They monitor the chemical composition of blood, particularly the levels of carbon dioxide (CO2), oxygen (O2), and pH, and they play a crucial role in the regulation of ventilation.

When there is an increase in carbon dioxide levels, these peripheral chemoreceptors respond by signaling the respiratory center in the brain to increase the rate and depth of breathing, facilitating the removal of CO2 from the body. This mechanism is essential for maintaining homeostasis in the body's acid-base balance and ensuring an adequate supply of oxygen.

Centrally located chemoreceptors also play a role in detecting CO2, but they primarily respond to changes in pH resulting from CO2 levels in the cerebrospinal fluid (CSF), influencing respiratory drive in a more indirect way. Thermoreceptors and baroreceptors, while important for other physiological functions, do not specifically detect changes in carbon dioxide levels. Thermoreceptors respond to temperature changes, and baroreceptors are involved in sensing blood pressure changes.