| Namespace | MPheno.ontology | Obsolete | false |
| description | any structural anomaly of the balloonlike diverticulae of the embryonic pharyngeal endoderm that line the inside of the branchial arches; these paired endodermal evaginations develop in a craniocaudal sequence between the branchial arches, e.g. pouch 1 lies between arches 1 and 2; in mammals, there are four well-developed pairs of pouches (the fifth and sixth pair is vestigial or absent); the pouch endoderm reaches the branchial groove ectoderm to form the double-layer branchial membranes that separate them |
