part_of part of part of in taxon Chordata embryo pharyngeal arch system NCIT:C34248 A transient embryonic complex that comprises the pharyngeal arches, bulges of tissues of mesoderm and neural crest derivation through which pass nerves and pharyngeal arch arteries. The arches are separated internally by pharyngeal pouches, evaginations of foregut endoderm, and externally by pharyngeal clefts, invaginations of surface ectoderm. The development of the system ends when the stucture it contributes to are forming, which may include (depending on species) the thymus, thyroid, parathyroids, maxilla, mandible, aortic arch, cardiac outflow tract, external and middle ear[GO,modified]. embryonic pharyngeal complex EHDAA2:0000187 pharyngeal arch complex pharyngeal system pharyngeal arch region FMA:293041 UBERON:0008814 pharyngeal apparatus pharyngeal complex pharyngeal arches and clefts pharyngeal region of foregut multi organ part structure