part of part of develops_from embryo heart primordium cardiogenic plate (In vertebrates) The embryonic mesoderm is the source of both the cardiogenic plate, giving rise to the future myocardium as well as the endocardium that will line the system on the inner side.[well established][VHOG] EHDAA2:0000215 EMAPA:16106 TODO - check plate vs rudiment vs primordium vs endocardial tube. See XAO The first recognizable structure derived from the heart field UBERON:0004139 VHOG:0000975 cardiac crescent cardiogenic crescent heart rudiment myocardial plate uberon developing anatomical structure