7.2. Divisions of the Mediastinum

Dividing Up the Mediastinum

The mediastinum is subdivided into compartments, and each of these is given its own name. The compartments are listed below and also in the previous image.

  • Superior mediastinum
  • Inferior mediastinum, which has three parts: anterior, middle and posterior
The superior mediastinum is divided from the inferior mediastinum by the sternal plane – this is an imaginary line drawn from the sternal symphysis joint to the intervertebral disc between T4 and T5.

If you're in an exam and need to have an 'educated guess' about the location of a structure such as the trachea, think logically about it...the anterior mediastinum is really small and, well, anterior, so it definitely won't have the trachea in it. The middle mediastinum contains only the heart and pericardium, so it won't be the answer. Now we have two options left: the superior or posterior mediastina. Well, the trachea runs from the pharynx (throat) to its point of bifurcation at the sternal plane...and we've just learned that the area above the sternal plane is the superior mediastinum - this is your answer!