Chemoreceptors in the medulla of the brain are activated by

Chemoreceptors in the medulla of the brain are activated by high H⁺ and high pCO₂. The role of oxygen in the regulation of respiratory rhythm is quite insignificant. Moreover, only peripheral chemoreceptors (carotid bodies and aortic bodies) are sensitive to changes in pO₂. Central chemoreceptors in the medulla are not sensitive to changes in pO₂.