Pulmonary ligament is the term used for the fold that goes down. As the wrist is surrounded by the cuff of the coat, in the same manner the root of the lung is surrounded by the pleura.  From the root of the lung, pulmonary ligament stretches itself towards the diaphragm and the mediastinum. Few lymphatics and loose areolar tissue are contained wholly in the fold.

Functionality

The functionality of pulmonary ligaments are as follows:

  • It gives a dead space into which the pulmonary veins can enlarge during increased venous return as during exercise.
  • It enables the descent of the root of the lung with all the descent of diaphragm during motivation. Consequently, the apex of lung comes down from the rough suprapleural membrane making an empty space below the membrane. Now the apex of lung can enlarge into this empty space.