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 period known as the pax romana lasted approximately 200 years from the battle of Actium when Octavian defeated Anthony until the time of the Emperor Aurelius. In view of this the first and main character of the pax romana is the founder of it all, Octavian (Augustus).