Costomediastinal recess-the costomediastinal recess is an area right next to the cardiac notch, which is an indentation in the superior lobe of the left lung. this is where the medial area of the superior lobe of the left lung would tend to expand if it became very inflated. the lung would not enter the anterior mediastinum, which is an area between the two pleural sacs, bounded anteriorly by the sternum and posteriorly by the pericardium. the anterior mediastinum contains areolar tissue, sternopericardial ligaments, lymph vessels and nodes, but no lung tissue. the costodiaphragmatic recess is the recess at the inferior border of a lung. this is the space into which the inferior lobe of the lung would expand following deep inhalation. the cupola is the serous membrane lining the pleural cavity which extends above the level of the 1st rib into the root of the neck. the most superior portion of the superior lobe might expand into this space. the pulmonary ligament is the fold of pleura located below the root of the lung where the visceral pleura and the mediastinal parietal pleura are continuous with each other.