Functional morphology and physiology of slowly adapting pulmonary stretch receptors.
Since the original work by Hering and Breuer (1868) on slowly adapting pulmonary stretch receptors (SARs), numerous studies have demonstrated that these receptors are the lung vagal afferents responsible for eliciting the reflexes evoked by moderate lung inflation. SARs play a role in controlling breathing pattern, airway smooth muscle tone, systemic vascular resistance, and heart rate. Both anatomical and physiological studies support the contention that SARs, by their close association with airway smooth muscle, continuously sense the tension within the myoelastic components of the airways caused by lung inflation, smooth muscle contraction, and/or tethering of small intrapulmonary airways to the lung parenchyma. As a result, the receptor field location within the tracheobronchial tree of a SAR plays an important role in its discharge pattern, with variations in airway transluminal pressure and airway smooth muscle orientation being important modulating factors. The disruption of airway myoelastic components in various pulmonary diseases would be expected to alter the discharge pattern of SARs, and contribute to changes in breathing pattern and airway smooth muscle tone.
Schelegle
Edward S
ES
Department of Anatomy, School of Veterinary Medicine, University of California-Davis, Davis, California 95616, USA. esschelegle@ucdavis.edu
D000222:Adaptation, Physiological; D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D063385:Cannabinoid Receptor Modulators / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology; D063388:Endocannabinoids; D006801:Humans; D008168:Lung / Q000294:innervation / Q000502:physiology; D009431:Neural Conduction / Q000187:drug effects; D053284:Polyunsaturated Alkamides; D011661:Pulmonary Stretch Receptors / Q000033:anatomy & histology* / Q000187:drug effects / Q000502:physiology*; D011955:Receptors, Drug / Q000378:metabolism; D012018:Reflex; D014630:Vagus Nerve / Q000187:drug effects / Q000502:physiology
D001095:Arachidonic Acids; D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D053284:Polyunsaturated Alkamides; D011955:Receptors, Drug; D002211:Capsaicin; C078814:anandamide