<prompt> True about relations of thoracic esophagus ?Trachea posteriorlyAoic arch on right sideLeft bronchus anteriorlyThoracic duct on right side  <response>: Ans. isci.e., Ieft bronchus anteriorlyRef: Snells p. 128The relations of the thoracic pa of the esophagus from above downward are as follows:Anteriorly: The trachea and the left recurrent laryngeal nerve: the left principal bronchus which constricts it; and the pericardium, which separates the esophagus from the left atrium.Posteriorly : The bodies of the thoracic veebrae, the thoracic duct, the azygos veins, the right posterior intercostal aeries and at its lower end the descending thoracic aoa.Right side: The mediastinal pleura and the terminal pa of the azygos vein.Left side: The left subclan aery, the aoic arch, the thoracic duct the mediastinal pleura. 