part of part of dorsum subdivision of trunk dorsal trunk trunk back The part of the trunk that is in the dorsum[cjm]. EMAPA:35162 FMA:25056 MA:0000020 back of trunk UBERON:0011270 Wikipedia:Human_back dorsal part of trunk In humans, the subdivision of trunk which is demarcated from the trunk proper by the external surface of the posterolateral part of the rib cage, the anterior surface of the thoracic vertebral column and the posterior axillary lines, the external surface of the posterior abdominal wall; together with the trunk proper, it constitutes the trunk[FMA] dorsum of trunk