The afferent (sensory) endings for the Hering-Breuer reflex are mechanoreceptors located in the

Hering-Breuer Reflex: Receptor: Pulmonary stretch receptors lie within the smooth muscle of large and small airways (bronchi and bronchioles). Stimulus for receptor: Distension of the lungs, when TV is more than 1.5 L Afferent: Vagus nerve large myelinated fibers. The Hering-Breuer inflation reflex (also called inhibitoinspiratory reflex): Inflation of the lungs tended to inhibit fuher inspiratory muscle activity. Hering-Breuer Deflation reflex (or excito-inspiratory reflex): Deflation of the lungs tends to inhibit fuher deflation (initiate inspiratory activity). It decreases duration of expiration. Diving reflex: Stimulation of nasal or facial receptors with cold water elicits apnea, or cessation of breathing, and bradycardia. Head's paradox reflex: Inflation of the lungs augment fuher inflation J-Reflex (pulmonary C-fiber receptor): Discovered by: Indian physiologist AS Paintal in 1954. Location: Juxtapulmonary capillary (J) receptors are located in alveolar walls or, lung interstitial tissue close to pulmonary capillary. Afferent: The impulses pass up the vagus nerve in slowly conducting nonmyelinated fibers (pulmonary C-fiber receptors). Stimulus: pulmonary congestion and chemicals like capsaicin. Not stimulated under normal/resting ventilation. Response: Rapid shallow breathing, bradycardia, hypotension