part of part of develops_from multi-tissue structure embryo embryonic structure mesoderm-derived structure heart rudiment primitive heart tube EHDAA2:0001512 EHDAA:424 EHDAA:436 EMAPA:16208 EMAPA:16215 FMA:321916 Multi-tissue structure that arises from the heart rudiment and will become the heart tube. TAO:0000149 UBERON:0005498 ZFA:0000149 early primitive heart tube primitive heart tube uberon