pharyngeal arch pharyngeal arch 5 5 in XAO, called branchial arch 3 and df VP5 5th pharyngeal arch branchial arch 3 A conserved feature of all vertebrate embryos is the presence of a series of bulges on the lateral surface of the head, the pharyngeal arches; it is within these structures that the nerves, muscles and skeletal components of the pharyngeal apparatus are laid down. The pharyngeal arches are separated by endodermal outpocketings, the pharyngeal pouches.[well established][VHOG] A fifth arch never establishes itself in amniotes 5th visceral arch fifth visceral arch gill arch 3 TAO:0001600 ZFA:0001608 fifth pharyngeal arch The third in a series of paired bars in the wall of the pharynx, within which are formed the third aortic arch and the cartilage bar of the visceral skeleton, forms and supports the gills.[AAO] FMA:293045 XAO:0000451 SCTID:308771006 visceral arch 5 AAO:0010367 VHOG:0001204 third branchial arch UBERON:0003116