Vagus & Phrenic Nerves in the Thorax

The phrenic and vagus nerves take very different courses through the thorax — and the recurrent laryngeal nerves are a classic question. PHRENIC NERVE (C3,4,5) • Runs ANTERIOR to the lung root, on the pericardium (fibrous pericardium + mediastinal pleura). Motor to the diaphragm; sensory to pericardium/mediastinal pleura. VAGUS NERVE (CN X) • Runs POSTERIOR to the lung root → contributes to…