How is the rise in carbon dioxide level in blood detected?

The rise in carbon dioxide (CO2) levels in the blood is primarily detected by chemoreceptors located in the brainstem and in the carotid and aortic bodies. These chemoreceptors monitor changes in the pH of the blood, which decreases as CO2 levels increase, leading to a more acidic environment. When CO2 levels rise, the chemoreceptors send signals to the respiratory centers in the brain to increase breathing rate and depth, facilitating the exhalation of CO2 and restoring homeostasis. This feedback mechanism helps maintain proper respiratory function and acid-base balance in the body.