Pulmonary ligament

The root of the lung is covered in front, above, and behind by pleura, and that at its lower border the investing layers come into contact. Here they form a sort of mesenteric fold, the pulmonary ligament, which extends between the lower part of the mediastinal surface of the lung and the pericardium.

Just above the diaphragm the ligament ends in a free falciform border. It serves to retain the lower part of the lung in position.