The inferior mediastinum is a space continuous with the superior mediastinum (read more!) above. It extends from the transverse thoracic plane to the inferior thoracic aperture and diaphragm. 

The pericardium (read more!) further subdivides the inferior mediastinum into three compartments: 

• Anterior mediastinum (read more!) - lies between the sternum and pericardium;
• Middle mediastinum (read more!) - contains the heart covered by the pericardium;
• Posterior mediastinum (read more!)- lies between the pericardium and thoracic vertebrae.

Note: The transverse thoracic plane is a horizontal plane that passes through and connects the sternal angle to the intervertebral disc between the fourth and fiftth thoracic vertebrae. It divides mediastinum into two compartments - superior and inferior mediastinum.