<P> Structures within the thoracic cavity include: </P> <Ul> <Li> structures of the cardiovascular system, including the heart and great vessels, which include the thoracic aorta, the pulmonary artery and all its branches, the superior and inferior vena cava, the pulmonary veins, and the azygos vein </Li> <Li> structures of the respiratory system, including the Diaphragm, trachea, bronchi and lungs </Li> <Li> structures of the digestive system, including the esophagus, </Li> <Li> endocrine glands, including the thymus gland, </Li> <Li> structures of the nervous system including the paired vagus nerves, and the paired sympathetic chains, </Li> <Li> lymphatics including the thoracic duct . </Li> </Ul> <Li> structures of the cardiovascular system, including the heart and great vessels, which include the thoracic aorta, the pulmonary artery and all its branches, the superior and inferior vena cava, the pulmonary veins, and the azygos vein </Li> <Li> structures of the respiratory system, including the Diaphragm, trachea, bronchi and lungs </Li>

A chambered muscular organ that lies within the thoracic cavity is called​ the