Thoracic cavity

1. the lungs,
2. the heart,
3. the thoracic aorta,
4. the main pulmonary artery[?] and its branches,
5. the thymus gland,
6. the trachea and bronchi[?] and
7. the esophagus.

It contains the potential space called the pleural cavity and the mediastinum[?].

If the thoracic cavity is breached from the outside, as by a bullet wound or knife wound, a pneumothorax[?], or air in the cavity, usually results, often leading to one or both lungs collapsing and requiring immediate medical attention.