part of part_of part of part_of endoderm pharyngeal arch 2 2nd arch endoderm 2nd pharyngeal arch endoderm An endoderm that is part of a pharyngeal arch 2. EHDAA2:0000061 EMAPA:16274 EMAPA:16276 EMAPA:16278 In all vertebrates, the pharyngeal apparatus develops from a series of bulges found on the lateral surface of the head, the pharyngeal arches, which consist of a number of different embryonic cell types. Each arch has an external covering of ectoderm and inner covering of endoderm, and between these a mesenchymal filling of neural crest with a central core of mesoderm.[well established][VHOG] RETIRED_EHDAA2:0000065 UBERON:0005664 VHOG:0001108 uberon