Final answer:
The superior mediastinum is delimited by the thoracic cavity and contains structures such as the thymus gland, trachea, esophagus, superior vena cava, and aortic arch.
Step-by-step explanation:
The superior mediastinum is delimited by the thoracic cavity. It is the upper portion of the mediastinum, which is the central compartment of the thoracic cavity between the lungs. It contains structures such as the thymus gland, trachea, esophagus, superior vena cava, and aortic arch.