UPDATED: Root term meaning Thorax (Greek: [θώρακα] Chest plate or area covered by a chest plate). The thorax contains three areas, or regions, sometimes described as "spaces" (sic). These are two laterally situated pleural cavities, each containing a lung, and a median mediastinum, a large region containing the pericardium, heart, great vessels, thoracic duct, azygos venous system, esophagus, aorta, thymus, etc. The plural form for thorax is [thoraces].

Thoracotomy: Opening of the thorax. Note that the term "thoratomy" en vogue nowadays is a misuse of the term
Thoracocentesis: The suffix [-(o)centesis) means needle aspiration. Needle aspiration of the thorax
Thoracoscopy: Visualization of the thorax

Personal note: There is a tendency, a trend to use the word [thorascopy]  instead of the correct form [thoracoscopy]. The use of [thorascopy] is incorrect and should not be allowed in the clinical arena. In fact, it is not recognized by my medical spellchecker! Dr. Miranda

Image property of: CAA.Inc.Artist: D.M. Klein
Thorax, anterior view