what is hilum

In human anatomy, the hilum is a depression or fissure where structures such as blood vessels and nerves enter an organ). The hilum of the lung is where airways, blood vessels, and nerves enter the lungs. It is located between the fifth and seventh thoracic vertebrae in the spine and is visible as a triangular section at the inner midpoint of each lung. The hilum carries critical vessels to and from the lungs and anchors each lung in place. It is triangular-shaped and surrounded by a pleura, which is a strong but delicate sac-like membrane that helps the lungs expand and contract with each breath and contains pleural fluid that lubricates this movement. The hilum of the lung is susceptible to disease, and masses caused by conditions like cancer can occur.