Nerves of superior mediastinum

The major nerves found in the superior mediastinum are as follows: phrenic nerves (originate from spinal cord segments C3 - C5, pass inferiorly over the anterior scalene muscle on each side and anteroinferiorly over the root of the lung to innervate each dome of the diaphragm), vagus nerve (the tenth cranial nerve (CN X)), left recurrent laryngeal nerve and right recurrent laryngeal nerve (arise from the vagus nerve on each side).