ABSTRACT
This chapter concentrates on classic understanding of innervation and especially on the role of neuropeptides in humans. In addition to classical adrenergic and cholinergic mechanisms, there exists a third component of the autonomic nervous system, which is mediated by neither catecholamines nor acetylcholine and is thus called the "nonadrenergic noncholinergic nervous system". There is abundant physiological evidence that the airway smooth muscle in humans is under cholinergic constrictor control. The neurotransmitter, acetylcholine, released from the cholinergic nerves, binds to muscarinic receptors. Physiological studies show that the dominant innervation of submucosal glands is cholinergic and parasympathetic. Physiological studies suggest that the main control of the tracheobronchial vascular bed is sympathetic and adrenergic, with alfa-adrenoceptors mediating constrictor effects. In humans, Granule-Containing cells contain biogenic monoamine and peptide hormones. It has been proposed that the airway inflammation in asthma has a neurogenic nature owing to activation of C-fiber afferent nerve endings.
