<P> The Hering--Breuer inflation reflex, named for Josef Breuer and Ewald Hering, is a reflex triggered to prevent over-inflation of the lung . Pulmonary stretch receptors present in the smooth muscle of the airways respond to excessive stretching of the lung during large inspirations . </P> <P> Once activated, they send action potentials through large myelinated fibers of the vagus nerve to the inspiratory area in the medulla and apneustic center of the pons . In response, the inspiratory area is inhibited directly and the apneustic center is inhibited from activating the inspiratory area . This inhibits inspiration, allowing expiration to occur . </P> <P> The Hering--Breuer inflation reflex should not be confused with the deflation reflex discovered by the same individuals, Hering and Breuer . The majority of this page discusses the inflation reflex; the deflation reflex is considered separately at the end . </P> <P> Josef Breuer and Ewald Hering reported in 1868 that a maintained distention of the lungs of anesthetized animals decreased the frequency of the inspiratory effort or caused a transient apnea . The stimulus was therefore pulmonary inflation . </P>

Where are the stretch receptors for the breuer–hering reflex located