<prompt> Which of the following statement is true in the mediastinum:The left brachiocephalic vein passes posterior to the brachiocephalic aeryThe ligamentum aeriosum inter-connects the aoic arch and the left pulmonary veinThe left recurrent laryngeal nerve passes under the arch of aoaThe thoracic duct is found between the oesophagus and the trachea  <response>: The left recurrent laryngeal nerve passes under the arch of aoa. Ligamentum aeriosum is the fibrous remnant of ductus aeriosus, of fetus, a channel that sho circuited the lungs. It passes from commencement of left pulmonary aery to the concavity of aoic arch beyond the point where left subclan aery branches off. The left recurrent laryngeal nerve hooks around it. The left brachiocephalic vein passes anterior to the brachiocephalic aery Thoracic duct traverses the diaphragm at the aoic apeure T12 and ascends the superior and posterior mediastinum between the descending thoracic aoa to its left and the azygos veinto its right. 