A thin membrane that separates the external ear from the middle ear, consisting of two epithelia (one part of the the external accoustic meatus epithelium, the other part of the tympanic cavity epithelium) with a fibrous layer between them. Its function is to transmit sound from the air to the ossicles inside the middle ear. The malleus bone bridges the gap between the eardrum and the other ossicles. Rupture or perforation of the eardrum can lead to conductive hearing loss. [WP,unvetted].
Comment:
[development-note] "The tympanic membrane (TM) has three layers, two epithelia provided by the external acoustic meatus (EAM) and the MEC, derived respectively from the first pharyngeal cleft and pouch, and a mesenchymally derived fibrous stratum"; [homology-note] "In particular, a tympanic membrane was not present in the earliest tetrapods (...). An ear utilizing a tympanic membrane evolved independently at least three times in tetrapods: (1) in the lineage that leads to anurans (frogs), (2) in the line of evolution to turtles and diapsids, and (3) in the late synapsid lineage that gave rise to mammals.[well established][VHOG]" xsd:string {date_retrieved="2012-09-17", external_class="VHOG:0001146", ontology="VHOG", source="ISBN:978-0030223693 Liem KF, Bemis WE, Walker WF, Grande L, Functional Anatomy of the Vertebrates: An Evolutionary Perspective (2001) p.418", source="http://bgee.unil.ch/"}
Synonyms:
exact_synonym:
Rivinus' membrane; ear drum; eardrum; lateral wall of tympanic cavity; membranous wall of tympanic cavity; myrinx; paries membranaceus cavi tympani