The document summarizes the major body cavities and their contents. It describes the dorsal cavity which contains the brain and spinal cord, including the cranial and spinal cavities. It also outlines the ventral cavity containing the thoracic and abdominopelvic cavities. The thoracic cavity is superior to the diaphragm and contains the lungs, heart and mediastinum. The abdominopelvic cavity is inferior to the diaphragm and contains the abdominal organs and pelvic organs.