text: The<unk>  is a non-delineated group of structures in the thorax (chest), surrounded by loose connective tissue.  It is the central compartment of the thoracic cavity. It contains the heart, the great vessels of the heart, esophagus, trachea, thymus, and lymph nodes of the central chest.
option_0: Mediastinum
option_1: Thoracic cavity
option_2: Chest
option_3: Hilum of lung
option_4: Bronchus
option_5: Tracheal bronchus
option_6: Neck
option_7: Mediastinal pleura