Pulmonary stretch receptor (and cough receptor, respiratory tract)

Pulmonary stretch receptors are mechanoreceptors located within the airway walls, predominantly in the lung periphery, that sense lung inflation and mediate the Hering-Breuer reflex to limit inspiratory time via vagal afferents to the medulla[3][1][2][6][7]. These receptors promote bronchodilation and decrease respiratory rate as lung volume increases. Cough receptors (including irritant and polymodal nociceptor-like endings) are found in the airway epithelium and subepithelium; they detect chemical and mechanical irritants and mediate protective cough, bronchoconstriction, and shallow breathing responses, again via vagal afferents[7][6]. These receptors help defend against inhaled toxins, pathogens, and mechanical damage, and play critical roles in diverse airway diseases. Both classes of receptors are vital sensors in the reflex control of breathing, airway tone, and defensive mechanisms in the respiratory tract, but should be considered as related yet distinct molecular and physiological entities[3][6][7].

Other names

Pulmonary stretch receptorSlowly adapting receptor (SAR)Rapidly adapting receptor (RAR)Irritant receptorC-fiber receptorCough receptorHering-Breuer receptorDefensive respiratory receptor

Inhibition of sensory neuron excitability (antitussives, anesthetics). Bronchodilation (reducing stretch receptor signaling via smooth muscle relaxation). Suppression of neurotransmission in cough reflex arc.