Chemoreceptors in respiration. Computer illustration showing the chemoreceptors (chemosensors, small, blue, oval) in the chest and brain of a woman that are involved in the regulation of breathing. Chemoreceptors are sensory receptors that receive a chemical signal and convert (transduce) it into a nerve signal. Certain chemoreceptors, known as acid-sensing ion channels (ASICs), detect the level of carbon dioxide (CO2) in the blood and send signals to the respiratory centre in the medulla of the brain in order to increase breathing rate and lung volume when CO2 levels are high.