Parasympathetic pulmonary nerve

The parasympathetic pulmonary nerve, more accurately described as the *pulmonary branches of the vagus nerve* or *parasympathetic innervation to the lungs*, is not a single molecule or receptor, but rather refers to bundles of autonomic nerve fibers that provide parasympathetic input to lung tissue. These fibers originate primarily from the vagus nerve (cranial nerve X), which carries preganglionic axons from brainstem nuclei. After synapsing in small ganglia near or within the lungs, postganglionic fibers release acetylcholine onto target cells. In pulmonary tissues: - Acetylcholine acts mainly via **muscarinic M3 receptors on airway smooth muscle**, causing **bronchoconstriction**, and on glandular cells to stimulate mucus secretion. - This system helps regulate baseline airway tone and secretions under normal conditions (“rest and digest”), counterbalancing sympathetic bronchodilation. - Dysregulation contributes to diseases such as asthma through excessive constriction/mucus production. Because this term describes an anatomical pathway rather than a discrete molecular entity: - It is **not considered a therapeutic target itself**, though its downstream effectors—such as muscarinic M3 receptors—are well-established drug targets for respiratory disease management. - The term “parasympathetic pulmonary nerve” is therefore imprecise for structured pharmacological databases focused on molecules/receptors. If you are seeking information about druggable targets within this pathway, refer instead to: - Muscarinic acetylcholine receptor M3 - Vagus nerve function/modulation This entry should be flagged as incorrect for use as a canonical molecular target name. Abnormalities at any point along this neural pathway—from central control through ganglia down to effector cell response—can contribute to pathologies like asthma by altering normal patterns of bronchomotor tone and secretion.[2] Drugs targeting downstream muscarinic receptors are used clinically; direct modulation at the level of these nerves themselves is less common outside experimental settings.[4]

Other names

Pulmonary branch of the vagus nerveparasympathetic innervation of the lungbronchopulmonary parasympathetic fibers

Anticholinergics block muscarinic acetylcholine receptors on airway smooth muscle, inhibiting bronchoconstriction mediated by these nerves - Cholinesterase inhibitors increase acetylcholine levels at synapses, enhancing parasympathetic signaling[4]