title: Localization of irritant receptors in the airways of the dog.
abstract: In dogs the authors have recorded from single fibres of the vagus nerve the action potentials originating from rapidly adapting receptors (irritant receptors) of the tracheo-bronchial tree activated both by inflation and deflation and by i.v. injection of histamine. A gross localization between extrapulmonary airways was established for 196 such receptors by probing the structures containing them. For 82 receptors a precise localization was determined within the extrapulmonary airways and for 51 receptors, localized in the lung parenchyma, a further precise localization was established along the intrapulmonary airways be dissecting the lung tissue. 66.9% of these receptors were found to be in the intrapulmonary airways and 33.1% in the extrapulmonary airways. Their distribution along the tracheo-bronchial tree resulted as follows: 4.75% in the higher 2/3 of the trachea, 9.25% in the lower 1/3 of the trachea and the carina, 19.0% in the main bronchus, 25.0% in the lobar bronchi, 36.8% in bronchi having a diameter larger than 1 mm and 5.2% in bronchi having a diameter smaller than 1 mm. Therefore the concentration of irritant receptors increases going from the upper trachea to the lobar bronchi and then sharply decreases reaching the smaller airways.
mesh_terms: D000200:Action Potentials; D000818:Animals; D001980:Bronchi / Q000294:innervation*; D004285:Dogs; D012119:Respiration; D011984:Sensory Receptor Cells / Q000502:physiology*; D014132:Trachea / Q000294:innervation*; D014630:Vagus Nerve / Q000502:physiology