Abstract
Specimens were obtained from resected lung lobes which had no diffuse lung diseases. The nerves were classified into adrenergic nerves, cholinergic nerves, and nonadrenergic inhibitory nerves on the basis of the ratio of small agranular vesicles (SAGV), large granular vesicles (LGV), and small granular vesicles (SGV). The result was that at the level of the segmental bronchus, cholinergic nerves and nonadrenergic inhibitory nerves were distributed in the bronchial smooth muscle, the bronchial gland, the smooth muscle of the bronchial artery, and the smooth muscle of the pulmonary artery. In particular, direct contacts were observed between the nerve fibers and the bronchial smooth muscle cells, the bronchial gland cells, and the myoepithelial cells. On the contrary, adrenergic nerves were sparse. It was concluded that the innervation of the bronchial muscle, the bronchial gland, the pulmonary artery, and the bronchial artery is mainly by the cholinergic nervous system and the nonadrenergic inhibitory nervous system.
