Superior mediastinum (overview)

The superior mediastinum is located behind the manubrium of the sternum and anteriorly to the bodies of the first four thoracic vertebrae (T1 - T4). It is continuous with the neck above and the inferior mediastinum below. 

The boundaries of the superior mediastinum are considered the following:

The superior mediastinum contains the following structures: esophagus, trachea, thymus, several nerves (phrenic nerve, vagus nerve (CN X), left recurrent laryngeal nerve), superior vena cava, brachiocephalic veins, aortic arch and its branches and thoracic duct.