Difference Between Hilum and Root of Lung

The key difference between Hilum and Root of Lung is that the Hilum of the lung is the large depressed area that lies near the centre of the medial surface while the Root of Lung is the all structures entering or leaving the lung at the hilum, forming a pedicle.

Lungs are the respiratory organs of our body. There are two lungs. Each lung connects into the trachea via a bronchus. Right bronchus brings air to right lung while left bronchus brings air to the left lung. Lungs are situated in the thoracic cavity and mediastinum separates the right and left lungs from each other. There are four main components of each lung. They are apex, base, root and hilum. The root of the lung situates in the hilum of each lung.

CONTENTS

1. Overview and Key Difference
2. What is Hilum of Lung
3. What is Root of Lung
4. Similarities Between Hilum and Root of Lung
5. Side by Side Comparison – Hilum vs Root of Lung in Tabular Form
6. Summary

What is Hilum of Lung?

The hilum is the triangular depressed area that allows the entry of bronchus, blood vessels, and nerves. Through the hilum, the root of the lung enters and exits the lung. It situates in the centre of the medial surface. Each lung has a hilum (plural – hila). Hence, our body has two hila. Both hila are similar in size, with the left hilum usually found slightly higher in the chest than the right hilum.

Tumors can occur in the area of hilum. Furthermore, the enlargement of hilar lymph nodes, as well as abnormalities of the pulmonary arteries or veins can happen.

What is Root of Lung?

The root of the lung is the structures that enter and exit at the hilum area. Therefore, each lung has its own root in the lung. Bronchus, pulmonary artery, pulmonary veins, lymphatics and nerves together make the root of each lung.

Figure 01: Root of Lung

Furthermore, there is a difference between right and left roots of the lungs. Pulmonary artery locates before the bronchus in the left root of the lung. The root of lung connects the medial surface of the lung with the mediastinum. Surrounding the root of the lung in each lung, there is a tubular sheath derived from mediastinal pleura.

What are the Similarities Between Hilum and Root of Lung?

  • Each lung has one hilum and one root of the lung.
  • Both are located at the medial surface of the lung.

What is the Difference Between Hilum and Root of Lung?

The main difference between hilum and root of lung is that the hilum is an area of the lung in which the root of lung enters and exits the lung. Bronchus, pulmonary artery, pulmonary veins, lymphs and nerves collectively make the root of the lung. Each lung has a hilum and root of the lung. However, the right and the left root of the lungs are not identical. Two hila are similar in size but differ slightly at the location.

Summary – Hilum vs Root of Lung

Hilum and root of the lung are two components of the lungs. The hilum is an area while the root of the lung is the structures that enter and exit through the hilum. Both are on the medial surface of the lung. Each lung has a hilum and root of the lung. The right and the left root of the lung is not identical due to the pulmonary artery. This is the difference between hilum and root of the lung.

Reference:

1.Eldridge, Lynne. “What Happens When the Hilum of Lung Has Abnormalities?” Verywell Health, Verywellhealth. Available here
2.“Root of the Lung.” Wikipedia, Wikimedia Foundation, 31 July 2018. Available here  

Image Courtesy:

1.’Blausen 0865 TracheaAnatomy’By :Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work, (CC BY 3.0) via Commons Wikimedia