Return to the mediastinum. (G 3.24;N 190;Gl 9.2A)

1. Peel and discard the mediastinal pleura. Clean the right and left phrenic nerves. The phrenic nerves are located between the mediastinal pleura and the fibrous pericardium.   Trace the phrenic nerve from the superior thoracic aperature to the diaphragm.   The right phrenic nerve is  often more difficult to locate than the left phrenic nerve.
2. Identify the arch of the aorta on the left side of the superior mediastinum. (G 3.45;N 209;Gl 9.6B) Identify and clean the left vagus nerve where it crosses (left) the arch of the aorta. Identify the left recurrent laryngeal nerve passing inferior to the arch of the aorta. Identify the ascending aorta, left pulmonary artery and the pulmonary trunk. Clean between the arch of the aorta and the pulmonary trunk adjacent to the left recurrent laryngeal nerve. Identify the ligamentum arteriosum (remnant of the fetal ductus arteriosum).
3. Identify the superior vena cava, arch of the azygos vein and inferior vena cava on the right side of the pericadial sac. The azygos vein arches directly superior to the right main bronchus before draining into the superior vena cava.