Mediastinum

superior

thoracic/lymphatic ducts

esophagus

trachea

root of lung

CN X

phrenic nerve

diaphragm

along pericardium

primary bronchi

great vessels

arteries

veins

thymus

inferior

posterior

azygos/hemi-azygos veins

thoracic duct

esophagus

thoracic aorta

middle

pericardium

heart

anterior

internal thoracic vessels

(thymus)