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://en.wikipedia.org/wiki/Tympanic_membrane http://www.ncbi.nlm.nih.gov/pubmed/11237469 ]
Synonyms: Rivinus' membrane myrinx membranous wall of tympanic cavity paries membranaceus cavi tympani ear drum eardrum lateral wall of tympanic cavity
Term information
- Wikipedia:Tympanic_membrane
- GAID:870
- NCIT:C12502
- SCTID:181180005
- EMAPA:19062
- FMA:9595
- MA:0000257
- MESH:D014432
- XAO:0000212
- UMLS:C0041445 (ncithesaurus:Tympanic_Membrane)
- VHOG:0001146
uberon_slim, pheno_slim, organ_slim
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
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]
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.
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]
Term relations
- membrane organ
- cellular anatomical structure
- overlaps some external acoustic meatus
- has part some outer epithelial layer of tympanic membrane
- contributes to morphology of some middle ear
- overlaps some external ear
- has part some inner epithelial layer of tympanic membrane
- develops from some pharyngeal membrane of 1st arch
- has part some intermediate layer of tympanic membrane
- adjacent to some tympanic cavity
- part of some middle ear