A broad, median partition. It is a space located between the lungs and extends from the sternum to the vertebral column and from the neck to the diaphragm. It contains the heart, esophagus, and trachea.

• A. Mediastinum cavity
• B. Pericardial cavity
• C. Pleural cavity
• D. Abdominal cavity

Answer: (A)

The central compartment of the thoracic cavity, between the lungs, is the mediastinum. It runs from the sternum to the vertebral column and from the neck down to the diaphragm, and it houses the heart, esophagus, and trachea. The pericardial cavity is a small space around the heart within this region, not the entire area. The pleural cavities surround the lungs on either side, and the abdominal cavity lies below the diaphragm. So the described broad, median space is the mediastinum.