In my book they describe root of the lung like this:
In the region of vertebrae TV to TVII, the mediastinal pleura refects off the mediastinum as a tubular, sleeve-like covering for structures (i.e., airway, vessels, nerves, lym-phatics) that pass between the lung and mediastinum. This sleeve-like covering, and the structures it contains, forms the root of the lung.
And hilum of the lung like this: The root joins the medial surface of the lung at an area referred to as the hilum of the lung. Here, the mediastinal pleura is continuous with the visceral pleura.
I dont see the difference between Root and hilum. Can somebody please help me out?