TABLE 1.
Summary of vagal bronchopulmonary sensory nerves
| Sensory Nerve | Conduction Velocity | Ganglion | Activation Stimulus | Reflexes |
|---|---|---|---|---|
| Stretch-sensitive | ||||
| SAR | Aδ-Aβ 10–50 m/s | Nodose | Lung inflation | Decrease parasympathetic outflow (bronchodilation) |
| Hering-Breuer Reflex Dyspnea (?) | ||||
| RAR | Aδ-Aβ 10–50 m/s | Nodose | Lung inflation and deflation | Increase parasympathetic outflow (bronchoconstriction, mucus) |
| Decrease in lung compliance | Tachypnea | |||
| Vascular congestion | Cough (?) mm | |||
| Nociceptors | ||||
| Extrapulmonary touch-sensitive mechanosensors |
Aδ 3–8 m/s | Nodose | Punctiform mucosal perturbations | Cough |
| Acidic solutions | ||||
| Bronchopulmonary C-fibers | C 0.3–2 m/s | Nodose | Inflammatory mediators | Increase parasympathetic outflow (bronchoconstriction, mucus) |
| Jugular | Tissue damage | Cough | ||
| Pulmonary edema | Apnea followed by tachypnea | |||
| Acidic solutions | Dyspnea |
Definition of abbreviations: RAR = rapidly adapting receptor; SAR = slowly adapting receptor.
The conduction velocities are approximate and may depend on species. The SAR fibers, RAR fibers, and bronchopulmonary C-fibers have been described in all mammals studied to date. The extrapulmonary touch-sensitive fibers have only recently been described and may not be present in all mammals. The activation stimuli listed are those most prominently associated with the nerve subtype.