Nerve supply to the lungs
- Receives afferent and efferent (parasympathetic preganglionic) fibers from the vagus nerve, joined by branches (sympathetic postganglionic fibers) from the sympathetic trunk and cardiac plexus.
- Is divided into the anterior pulmonary plexus, which lies in front of the root of the lung, and the posterior pulmonary plexus, which lies behind the root of the lung.
- Has branches that accompany the blood vessels and bronchi into the lung.
- Has sympathetic nerve fibers that dilate the lumina of the bronchi and constrict the pulmonary vessels, whereas parasympathetic fibers constrict the lumina,dilate the pulmonary vessels, and increase glandular secretion.
- Arises from the third through fifth cervical nerves (C3–C5) and lies in front of the anterior scalene muscle.
- Enters the thorax by passing deep to the subclavian vein and superficial to the subclavian arteries.
- Runs anterior to the root of the lung, whereas the vagus nerve runs posterior to the root of the lung.
- Is accompanied by the pericardiophrenic vessels of the internal thoracic vessels and descends between the mediastinal pleura and the pericardium.
- Innervates the fibrous pericardium, the mediastinal and diaphragmatic pleurae, and the
- diaphragm for motor and its central tendon for sensory.