QS Study

Anterior mediastinum

It is a very narrow space in front of the pericardium & is continuous with the pretracheal space of the neck. It contains most of the thoracic organs and acts as a conduit for structures traversing the thorax on their way into the abdomen. It is the portion of the mediastinum anterior to the pericardium and below the thoracic plane.


Anteriorly: Body of the sternum and the transversus thoracic muscles.

Posteriorly: Pericardium enclosing heart.

Superiorly: An imaginary plane separating the superior mediastinum from the inferior mediastinum.

Inferiorly: a Superior surface of the diaphragm.

On each side: Mediastinal pleura.

Fig: Boundaries and Contents of Anterior Mediastinum

Contents – It accommodates loose connective tissue including fat, some lymphatic vessels, lymph nodes and branches of the internal thoracic vessels.

  • Sternopericardial ligaments.
  • Lymph nodes with lymphatics.
  • Small mediastinal branches of the internal thoracic.
  • Parts of thymus gland or its remnant.
  • The lowest part of the thymus.
  • Areolar tissue.
  • The lower portion of the thymus (in children).