The inferior mediastinum is a space continuous with the superior mediastinum above and extends to the inferior thoracic aperture and diaphragm below. 

The pericardium further subdivides the inferior mediastinum into: 

• Anterior mediastinum - lies between the sternum and pericardium

• Middle mediastinum - consists of the heart and pericardium

• Posterior mediastinum - lies between the pericardium and the thoracic vertebrae