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]. [ http://www.ncbi.nlm.nih.gov/pubmed/11237469 http://en.wikipedia.org/wiki/Tympanic_membrane ]

Synonyms: Rivinus' membrane myrinx membranous wall of tympanic cavity paries membranaceus cavi tympani eardrum ear drum lateral wall of tympanic cavity

This is just here as a test because I lose it

Term information

Subsets

uberon_slim, pheno_slim, organ_slim

latin term
paries membranaceus cavi tympani [ FMA:TA FMA:9595 ]

development notes

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

external definition

The thin membrane which closes externally the cavity of the middle ear and is deeply sited at the bottom of the external auditory meatus. [Dorian_AF, Elsevier's_encyclopaedic_dictionary_of_medicine, Part_B:_Anatomy_(1988)_Amsterdam_etc.:_Elsevier][VHOG]

external ontology notes

most AOs consider this part of the middle ear, so we go with this and place it in the middle ear as a border to the external, although it could be considered to overlap the external ear in that it has an EAM layer as part - for this reason we do not consider middle and external ear to be spatially disjoint.

homology notes

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]

id

UBERON:0002364