Do axon reflexes exist within the lung?
Circumstantial evidence is given in support of the hypothesis that vagal lung receptors are involved in local axon reflexes. All the components of such mechanisms are present, and teleologically it would make sense for them to exist. It is suggested that rapidly-adapting or irritant receptors produce local muscle relaxation as well as the centrally-mediated reflex bronchoconstriction in other parts of the lung. Conversely, it is suggested that slowly-adapting pulmonary stretch receptors produce the opposite effect - local bronchoconstriction and centrally-mediated reflex bronchodilatation. The third group of receptors - the non-myelinated endings or J receptors - probably behave like the rapidly-adapting receptors. The mechano, chemo, and nociceptive reasons for these local axon reflexes are presented, and the difficulties of testing their existence is discussed.
D001369:Axons / Q000502:physiology*; D002628:Chemoreceptor Cells / Q000502:physiology; D008168:Lung / Q000294:innervation*; D009619:Nociceptors / Q000502:physiology; D011661:Pulmonary Stretch Receptors / Q000502:physiology; D012018:Reflex / Q000502:physiology*; D011984:Sensory Receptor Cells / Q000502:physiology*; D014630:Vagus Nerve / Q000502:physiology