Return to the mediastinum. (G 3.24;N 190;Gl 9.2A)
- Identify the right and left phrenic nerves. Trace the phrenic nerve from the superior thoracic aperature to the diaphragm.
- 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. Identify the ligamentum arteriosum (remnant of the fetal ductus arteriosum).
- Identify the superior vena cava, arch of the azygos vein and inferior vena cava on the right side of the pericadial sac.
Important Relationships
- The left phrenic nerve passes anterior to the root of the left lung.
- The left phrenic nerve is positioned lateral to the pericardial sac.
- The left phrenic nerve passes lateral to the ascending aorta.
- The right phrenic nerve is positioned lateral to the superior vena cava.
- The right phrenic nerve is positioned lateral to the pericardial sac.
- The right phrenic nerve passes anterior to the root of the right lung.
- The arch of the aorta passes superior to the pulmonary trunk.
- The left vagus nerve passes directly lateral to the arch of the aorta.
- The left recurrent laryngeal nerve passes posterior to the ligamentum arteriosum.
- The left recurrent laryngeal nerve passes directly inferior to the arch of the aorta.
- The left vagus nerve passes posterior to the left main bronchus.
- The right vagus nerve is positioned lateral to the trachea.
- The right vagus nerve passes medial to the arch of the azygos vein and posterior to the right main bronchus.
- The superior vena cava is positioned lateral (right) to the ascending aorta.
- The azygos vein (arch) passes superior to the right main bronchus.
