Mediastinum

• The mediastinum, though thick, is a movable partition that extends superiorly to the thoracic outlet and the root of the neck and inferiorly to the diaphragm.
• It extends anteriorly to the sternum and posteriorly to the vertebral column

Contents

• Remains of the thymus
• Heart and large blood vessels
• Trachea
• Esophagus
• Thoracic duct
• Lymph nodes
• Vagus and phrenic nerves
• Sympathetic trunks

Superior Mediastinum

The superior mediastinum is bounded in front by the manubrium sterni and behind by the first four thoracic vertebrae.

Contents include:

• Thymus
• Large veins
• Large arteries
• Trachea
• Esophagus and thoracic duct
• Sympathetic trunks

Inferior Mediastinum

The inferior mediastinum is bounded in front by the body of the sternum and behind by the lower eight thoracic vertebrae.

Contents include:

• Thymus
• Heart within the pericardium with the phrenic nerves on each side
• Esophagus and thoracic duct
• Descending aorta
• Sympathetic trunks

Clinical Notes

• Deflection of Mediastinum
• Mediastinitis
• Mediastinal Tumors or Cysts
• Mediastinoscopy