| Namespace | MPheno.ontology | Obsolete | false |
| description | any structural anomaly of the first endodermal branchial pouch located between the first and second branchial arches; in mammals, the first pouch elongates to form a diverticulum known as the tubotympanic recess; the distal portion of this recess expands to reach the first branchial groove and form the middle ear cavity (aka tympanic cavity) and mastoid antrum; its proximal part remains tubular and forms the auditory tube (aka Eustachian or pharyngotympanic tube), which forms a communication between the nasopharynx and tympanic cavity |
