Hilum (anatomy)

Hilum (anatomy)

The hilum (plural: hila) is a term used in anatomy to describe a part of an organ where structures such as blood vessels, nerves, and ducts enter or exit. It is often used in reference to the lungs, kidneys, and lymph nodes, but can apply to other organs as well.

Structure and Function

The hilum serves as a gateway for the transportation of essential substances in and out of an organ. It is typically located on the medial side of an organ, where it forms a depression or indentation.

Lungs

In the lungs, the hilum is the site where the bronchi, pulmonary arteries, pulmonary veins, and lymphatic vessels enter and exit. This area is also known as the root of the lung.

Kidneys

The hilum of the kidney is the point of entry and exit for the renal artery, renal vein, and ureter. It is located on the medial side of the kidney, facing towards the spine.

Lymph Nodes

In lymph nodes, the hilum is the indented region where lymphatic vessels and blood vessels enter and exit. It is also the site where efferent lymphatic vessels leave the node.

Clinical Significance

Changes in the appearance or size of the hilum can indicate various medical conditions. For example, enlarged hila may suggest lymphadenopathy or lung cancer. Therefore, the hilum is often examined in medical imaging studies such as CT scans and X-rays.

See Also

• Anatomy
• Lung
• Kidney
• Lymph node