<prompt> Which of the following forms Anterior boundary of Middle mediastinum?Sterno-pericardial ligamentsOesophagusAzygos veinDescending thoracic aoa  <response>: BOUNDARIES OF MIDDLE MEDIASTINUM: Anteriorly - sterno-pericardial ligaments Posteriorly - esophagus, descending thoracic aoa, Azygos vein On each side - Mediastinal pleura 