The mediastinum is the gap in the thoracic cavity of the lungs. It separates the two laterally placed pleural cavities.
The pleural sacs of the lungs
The Mediastinum separates the thoracic cavity into two compartments.
Diaphragm which is the most important muscle for breathing, separates lungs from abdomen
The space between the 2 lungs is called the Mediastinum where the heart is located
the newest nomenclature says that mediastinum is divided in 4 parts: -mediastinum anterius, -mediastinum posterius, -mediastinum superius and -mediastinum inferius. Mediastinum inferius is divided in 3 parts (anterius, medius and posterius);
i think that your lungs would be dried out.
The mediastinum is found in the thoracic cavity.