Definition of Mediastinum. Mediastinum: The area between the lungs. The organs in the mediastinum include the heart and its large veins and arteries, the trachea, the esophagus, the bronchi, and lymph nodes. Search MedTerms:
The Pax Romana ended because the Roman state had ceased to grow. Boundaries had been set for the Empire, and for the first time the army had become a drain on the econom â¦ y of Rome. Till this point the army provided new slaves and riches from conqured countries.
The Pax Romana was a period of of relative political stability. It was followed by the political instability of the crisis of the 3rd century. it was also the beginning of the decline of the Roman Empire which lasted for nearly 300 years.he Pax Romana was a period of of relative political stability. It was followed by the political instability of the crisis of the 3rd century. it was also the beginning of the decline of the Roman Empire which lasted for nearly 300 years.