Also found in: Medical.
respiratory reflexes that arise during inhalation and exhalation; an essential element in respiratory self-regulation. The reflexes were described by the German physiologists E. Hering and J. Breuer in 1868. During inhalation the lungs expand, causing stimulation of the mechanoreceptors in the alveoli and in the intercostal muscles and the diaphragm, which are sensitive to mechanical stimulation of nerve endings. From the mechanoreceptors the nerve impulses travel along the vagus nerve, enter the respiratory center of the medulla oblongata, and cause excitation of the neurons, leading to relaxation of the muscles and exhalation. The greater the lung expansion, the more nerve impulses enter the respiratory center, leading to cessation of inhalation and initiation of exhalation. Cessation of these impulses again stimulates inhalation.