24.5 The Main Bronchi

• • The trachea divides into the right and left main bronchi.
• At T5, the trachea branches within the mediastinum, giving rise to the right main bronchi and left main bronchi
• An internal ridge, the carina of trachea, lies between the entrances to the two main bronchi
• The right main bronchus is shorter, has a larger diameter, and descends toward the lung at a steeper angle than the left
• Each main bronchus travels to and through the hilum of the lung before branching further
• The hilum is the site for the entry and exit of the pulmonary vessels and pulmonary nerves
• A meshwork of dense connective tissue anchors all of these structures to the lung
• Dense connective structure is called the root of the lung
• The root of the lung is attached to the mediastinum and holds the major nerves, vessels, and lymphatics in place
• How can you distinguish the right main bronchus from the left main bronchus?

  The right main bronchus is shorter, has a larger diameter, and extends toward the lung at a steeper angle than the left main bronchus.
• SUMMARY

  • Trachea branches within the mediastinum to form the right main bronchi and left main bronchi. The main bronchi and their branches form the bronchial tree. Each bronchus enters a lung at the hilum. The root of the lung is a connective tissue mass including the bronchus, pulmonary vessels, and nerves.