ABSTRACT
Autonomic neural regulation of airway function is complex, and even the classic cholinergic and adrenergic innervations are incompletely understood. This chapter reviews the functional autonomic innervation of the lung and focuses on the efferent cholinergic and adrenergic systems. The airways are richly innervated by the parasympathetic nervous system. Cholinergic efferent nerves arise in the vagal nuclei of the brain stem and travel in the vagus nerve to synapse in ganglia located within the airway wall. The chapter discusses the advances in defining muscarinic receptor subtypes that have advanced understanding of the regulation of cholinergic-mediated airway tone. The parasympathetic nervous system regulates glycoprotein and mucus secretion in airways. Secretory cells are innervated by a plexus of postganglionic fibers derived from both parasympathetic and sympathetic nerves. The sympathetic nervous innervation to the lungs originates from the first six thoracic preganglionic fibers that end in the lower cervical and first four thoracic ganglia.
