ClipArt ETC
"The transverse section of the thorax. 1, anterior mediastinum; 2, internal mammary vessels; 3, triangularis sterni; 4, 5, phrenic nerves; 6, thoracic duct; 7, esophagus; 8, vena azygos major; 9, thoracic aorta; 19, sympathetic; R. V., right ventricle; R. A., right auricle; P.A., pulmonary artery; A., aorta; C., superior vena cava; V., dorsal vertebra." — Richardson, 1906

Thorax

"The transverse section of the thorax. 1, anterior mediastinum; 2, internal mammary vessels; 3, triangularis…