<prompt> During cardiac surgery of a 45-year-old male the cardiac surgeon can place her fingers in the transverse pericardial sinus, if necessary. This allows the surgeon to easily place a vascular clamp upon which of the following vessels?Right and left pulmonary veinsSuperior and inferior vena cavaRight and left coronary arteriesPulmonary trunk and ascending aorta  <response>: A finger passing through the transverse pericardial sinus passes directly behind the great arteries exiting the heart, allowing the surgeon to rather easily place a vascular clamp upon the pulmonary trunk and ascending aorta. The other vessels listed are not readily accessible by way of the transverse sinus. 