part_of part of part of organism subdivision thoracic segment of trunk dorsal thoracic segment of trunk UBERON:0008231 upper back thoracic part of back thoracic back FMA:24217 posterior part of thorax dorsum of thorax MA:0000028 SCTID:362666008 Subdivision of thorax, which in humans is the posterior part of the thorax and is demarcated from the chest by the external surface of the posterolateral part of the rib cage and the anterior surface of the thoracic vertebral column; together with the chest, it constitutes the thorax. back of thorax dorsal trunk